20 LBC Desert Style

[GLSHOOTER]

I received one of the 20 LBC barrels for testing the first week of July. I started ordering parts to finish the upper and over the next ten days got a few things in. I picked up an Aero Precision upper and a 6.5 BCG from SAA, The Hogue FF tube and a Kies adjustable gas block came in from JoeBOb Outfitters out of Kansas, I got four magazines (two 5's and two 10's) from ASC out of Connecticut.





I boxed it all up and sent it to Ritch Johnson, one of the Pro Staff here, for assembly and here it is getting some sun in Utah.



Once I got it I put it on a lower I put together a couple of years ago with a nice 3 pound Timney trigger and a few other goodies. I've been using this lower on different varmint rigs and in some IPSC matches where it has done well for me.



I had ordered some 20 PPC dies on July 5 to make up the cases out of Hornady Grendel hulls but they did not come in so I got tired of waiting and ordered up a set of 22 PPC Redding Type S FL bushing dies about two weeks ago. I sat down when they came in and started teaching myself how to neck down the 6.5's and turn the necks so they would fit in the chamber. Here is a pic of my first rounds.



As there was no loading data for this one out there I selected a nice charge of TAC powder from 20 PPC data and figured it would be safe. I was being conservative on purpose. Rare for me but I do believe I want to be safe while I learn!!

Here is the range set up. Very minimalist approach with only the basics here.



First shot out of the barrel while getting on paper at 25 yards. The velocity is right what I expected out of this 20" barrel.



Lots of room for more powder and much higher velocities when I work this one up.

This is the three shot group after getting on paper with the first two rounds. Not bad considering I shot one and cleaned it between the first five shots. Not normally conducive to good groups but they seemed to want to play well. What do you think?



So what we have is a 0.670 outside reading giving up a 0.466 CTC for the first group out of the rifle!! 102 degrees, mild switching winds and tons of mirage. The gas block worked well as I adjusted it. The cases look super with, at this point, no signs of pressure.

I'll post more as this goes along.

Greg

[carvercalls]

Great write up Greg!! It looks like its going to be a shooter. What bullet are you shooting?

[GLSHOOTER]

Aug 15, 2011 3:39:04 GMT -8 carvercalls said:

Great write up Greg!! It looks like its going to be a shooter. What bullet are you shooting?

39 grain Sierra BK's and WIN 7 1/2 primers.

Greg

[GLSHOOTER]

Took the 20 LBC out for some more load work on Saturday. We had a mild day her so it was only 112 degrees. The wind were light though the occasional 25 MPH gusts did occur.

I had shot some TAC powder the week before and it did not perform well during the break in phase on the barrel. Velocities were outstanding with my test loads stopping at 3735 with no signs of pressure. I love speed but while it was only around 103 out I feel like it was reacting violently due to the temps. Velocity spreads were much more than I would normally see on weighed charges. I'll shelve the TAC until it cools down and reshoot it.

As I mentioned I took the rifle out again with a powder change to IMR 8208 XBR, hows that for a designation?, under the 39 grain Sierra BK that I have chosen to work with.

Grouping was better taking in to account my seeming inability to shot five good shots back to back with my rudimentary bench rest stuff showed 3 shot groupings from 0.400 to 0.854. Velocity started with a very cautious 3464 and stopped at 3691. The primer edges at the top showed an extremely mild lack of roundness. Compared to the starting loads I needed a 10 X loupe to see the changes!! No bright ejector marks were seen. This tells me that I have a ways to go on the powder charge. I think that this is definitely a powder that is doing well and it doesn't appear to be adversely effected by the high temperatures. As this is a 20" tube I am tickled with the speeds so far. I could stop now but like they say, That's not how I roll!!

I'll try a higher loading this next weekend and maybe another powder to start work with to. Dove season starts in three days so I have to fight that urge too!!

Greg

[GLSHOOTER]

Didn't make it to the range. Dove season ran over the LBC last weekend!! I loaded up another 48 rounds of the XBR powder for testing. The numbers should be interesting assuming it shoots well.

I also looked over all the load data I could find for the 20 PPC and some 22 PPC for ideas and have selected three other powders I want to try. That being the case I sat down on Tuesday and necked down my remaining 150 6.5 Grendel cases and turned them in to 20 LBC's.

I am now in the process of neck turning those cases. At the rate I am going with no power tools I am doing 30/hour so it is taking a bit of time. I really need to look at a powered case holder as these are not going to be the last cases I turn.

I'll post up some more numbers and results in the future. It is cooling off and is supposed to be only 110 today so I am back into my long sleeve T-shirts.

Greg

[GLSHOOTER]

Just a quick pic of the finished cases that I have made up in the past two days. I think that I can now start a Model T with a crank with the mere flip of my wrist after turning all 145 of the survivors!! I'll start loading up my three new powders today in preparation for my range time next week. I hope to shoot some more 8208 XBR tomorrow. These are turned to give me a finished 0.232 neck size.

THE PROCESS


THE REWARD


Greg

[GLSHOOTER]

Got to the range yesterday. It was basically a trip to regroup as my results had been hit and miss with my 20 LBC over the past few weeks. I've tried four powders and while I could get some velocity readings that were excellent without obvious pressure signs the groups just weren't settling in at all.

All loads shot until yesterday were with the 39 grain Sierra BK bullets (naked) I have been shooting this bullet in three 204's and a 20 Tactical for about four years with stellar results but it just wasn't working on this one. I looked at everything I could and finally decided I was too pig headed for my own good!! Finally capitulation to the cold hard facts of the caliper I drove on down and picked up four different bullet offerings. I picked up some 40 VMAX, 40 Bergers, 39 Speers and some 32 Sierras.

I had been pushing my loads hard and decided I needed to back down and try it from a low start and proceed with baby steps to a fieldable velocity. I also decided to try the IMR 82028 XBR powder on all the bullets with similar charges for each to make the testing field as level as I could make it.

I fired some more 39 Sierras to warm up and just to prove the barrel faeries had not visited me and , as expected, they had not!!

I tried the Hornady VMAX first off and right off the get go found out that it had a much longer ogive than the Sierra and I was in the lands!! Velocity on the starting load was a bit higher than it should have been and I was having trouble with the cartridges not seating. I thought that I had failed to set the shoulders right as this was new batch of brass.

I tried a few shots and was having a hard time with bolt lock up. I FINALLY got smart and looked at an extracted loaded round and found a slight burnishing on the bullet ogive. The velocities indicated they were a bit hot for that powder charge but not overly so so I finished up with a ten shot groups and called it god until I reseat the bullets for the next three laod levels. The two groups were right on an inch and I was ecstatic. I do believe we are on to something!!

I then shot the Berger 40's and suddenly things were working. Two groups at the lowest powder level were suddenly under one inch with some good looking holes. As I progressed I found the Bergers to do VERY well considering I was fighting a huge mirage issue. The cross hairs were showing a visual target movement of as much as 1/2" at 100 yards. Not conducive for little groups with a non-bench rest level shooter!!

I shot eight groups with the Bergers and the only issue I had was a first round out of group when I loaded from the magazine. A common problem with the AR platform and I will have to start whacking the forward assist on the next test date to see if that will lend some consistency. I have a 6 PPC AR and I have found this will decrease the movement a great deal. I'm trying to learn the vagaries of this rifle so am doing as little to induce as few changes as I can.

When the smoke cleared and I took a long drink, it was only 106 out, I found that if I eliminated the first round group expansion I was consistently under an inch and I also found several three shot groups that werr on the smallish side around 0.6.

At this point I had enough time to try the Speer 39 grain TNT's out. This one costs a bit more than the VMAX but less than the Bergers and I have had good luck with the 6 MM versions in my 243 over the years.

I was getting tired and figured it was time to wring out this tube with a bit of heat on board. Off the bench I had been babying the rifle and trying my best to control those twitches that seem to show up in the nervous system of old age. I went ahead and got on it this time with pressure on the gun and the mind set I would use if I were shooting a run and gun match. Shooting speed was reduced by about 50% and I only lett he barrel cool about five minutes between ten shot strings. I was listening as the the chronograph numbers climbed as I shot the heavier loads and my Leupold was telling me that things were going good down range!!

When I was done I found the barrel VERY hot. I had brass all over the ground and a few empty magazines. The calipers told me that I had just produced seven of eight groups under one MOA and I had half of the groups showing three shot groups in under one half an inch!! The best three shot cluster showed 0.109 for my efforts. Perhaps the shoot it like you stoled it mentality was the way to go. Maybe the conditions of the group development were more consistent when I sped up.

I do know that this rifle does not"walk" when it get hot as if I put all the groups on top of each other 36 rounds fired would have been held under a silver dollar and 34 would have been under a quarter. Shot hard this told me a few things. One, I have found that the Speers will shoot, two, that I can shoot relatively quickly and still have group integrity and, three, that once I whip the first round shot movement I am going to have one terrific varmint rifle on my hands. The first shots are not that far of and would be good on anything bigger than a prairie dog at reasonable range. I think this one will stretch out on PD's later next month and I can give an "on target" report.

I am putting this up as a status report to let everyone know the 20 LBC is starting to breath fire to match it's environment here in Phoenix. Ritch and Billy are shooting this too and with their superior shooting skills are making me look like a duffer!! My assessment at this point? We have a winner!! ;D

Greg

[Deleted]

Very nice post in deed!

Here is another 'desert style' I just finished....

[GLSHOOTER]

Lets see, where to start? I've been working with this one since mid-August and have been getting an eduction as I went! I put well over 300 rounds of Sierra BK's down range and no matter what happened I couldn't get those bullets together.

They say that insanity is doing the same thing over and over and expecting different results. Being a psych nurse I understand that!! So...I went in to therapy via telephone with a good therapist. Ritch, here on the board, was kind enough to listen to my delusional and almost psychotic babbling on my results and eased me through a rough patch that had me thinking about taking up black powder shooting and I HATE cleaning guns!!

We figured it was time to give up on the Sierras and try some more offerings. I picked up some Speers, Hornady and Berger 20 caliber bullets. I found that group sizes shrunk dramatically but were still inconsistent and I would throw a round 2 1/2" outside the center batch over and over again. I had a GREAT three shot group gun but not one that would do it at 300 yards on PD's on demand. Not good.

This went on for around 200 rounds and I still was not happy though I just knew that I was missing something. The cases had been turned the appropriate amount for the chamber but they were tight after firing to the point that you could not seat a bullet easily even with the unsized/fired neck. I figured what the heck and started twisting the screws on my neck turner. I did several test levels with thinner and thinner necks, applied less neck tension via bushing and even used a 204 specific expander on a batch. As the necks thinned the groups got better though I was still getting an occasional flyer but these were only about 1 1/4" now. There went another 100 rounds but like a kid at Christmas I knew there had to be ONE MORE present under the tree!!

I noted that my cases were giving me a lot better bullet release but still having some "tightness" in putting a bullet back in the non-sized necks. Could that inconsistent tightness be causing the slightly bigger than acceptable groups with the added flyer headache?

I already had the brass, I had the turner and I had nothing to loose on these cases as they are certainly not brand new anymore. I also knew that the other 20 LBC barrels out there are shooting lights out and that the potential of me getting a bad barrel was there but the likelihood, based on others results was at a very low level.

Making that determination out came the tools and I turned another thirty cases down to a thinner level. At this point my brass is 0.003 thinner than the original turned size. I loaded up ten each with a 0.204 expander mandrel, ten with a 204 button neck expander and ten with a 225 bushing. Off to the range!!

First batch looked better and after fouling got me about a 1.2. The second group with the 204 button shrunk down to 1.03. The third batch witha 227 neck and a 223 bushing was suddenly exciting. A 0.985 was looking good and the second one for this test was a disaster in the making as shots #2 and # 3 were wide at 1.4 thanks to my twitchieness. I got off the gun and let my nerves settle for a bit and did a little Zen mind clearing. Shots #4 and #5 popped in to the #1 hole. I was afraid to go down and look as I had been disappointed before. The caliper showed three shots in at 0.170. Not a five shot group but when I overlaid the two groups with the 223 bushing I found I had a nice 1.25 combination throwing out my two hammer the trigger issues. .

I checked for bullet release and found that I still had some that were a tad tight but virtually no resistance. I am going to be back on the range Friday with another thirty rounds that have been thinned further. Bases on my very inexpensive front rest and the weather conditions I do believe I am on the track. I did find thatt he first round movement of the bullet has decreased by about 90% and that shot #1 following a bolt drop is now very very close to the other rounds if not right among them. I have fought that issue since day one and I am now seeing it resolved. Perhaps the extra clearance is allowing the case to settle in a bit more consistently.

So far I have right on 550 rounds down range, I've used that many bullets, gone through 2 pounds of IMR 8208 XBR and have been wearing out 200 pieces of Hornady brass.

What have I learned? I have found I need to buy a power screwdriver attachment for my next neck turning evening. I found that the cases are holding up well and will take a lot of abuse. I have done a few very hot loadings and paid the price on primer looseness. I have found that velocities out of this 20" barrel will run right alongside my 204 and 20 Tactical 24" guns with no issues with pressure. Probably thanks to the long throat and the poly rifling. If this cartridge were put up in a 24" tube the velocities would be outstanding.

I am finding out that my rifle likes to have a bit more clearance in the neck than I would have expected. They are all individuals and this one just want to be a bit more free. I'm tickled pink that I am getting a handle on this and within the next thirty days I do believe I will have nailed down. Nothing wrong with the barrel just merely a matter of learning what this little wildcat is all about. If the barrel quality were poor I would never have a prayer in really seeing what this cartridge can do. I've been loading well over 30 years and this one has let me get down in to the deep intricacies of what makes a shooter vs an "acceptable" performer.

I'll post more as I get some load development done as the above tests were run with the same powder charge and it was a "starting load" level. Velocity was right on 3625 or so but it is way below the velocities I was getting previously. I believe it will tighten up more as I push the bullets and give the neck a bit more expansion room.

Greg