|
Post by ducksmasher on Jul 15, 2012 9:41:01 GMT -8
This is my first ar it is built with a BHW LH upper in 556 and 80% lower with WOA 26" bull barrel. I have been reading about piston systems and found that they drop accuracy of rifle due to the function. My question is will it cause the same problem when using the BHW railed upper or am I trying to re-invent the wheel here. I built The gun for p-dog hunting and with the probability of shooting 300-500 plus shots a day. I was hoping if i used a piston system all I would need to do is clean barrel every so many rounds with out disasymbling completely. I will have a other rifles with me as well but this will be the primary gun of choice. Thanks in advance
|
|
|
Post by Master Yoda on Jul 15, 2012 11:16:05 GMT -8
Yes the internally railed upper will change how the piston works. give it a try
|
|
|
Post by GLSHOOTER on Jul 15, 2012 16:41:31 GMT -8
Carl is the Master about the upper and I won't quibble with that!! That being said I've shot a few or those extended round counts without cleaning. I've run countless DI AR's past 400 rounds for cleaning, we used them at the BOP for qualifying and the AVERAGE round count between cleanings was 750+. That was barrel AND bolt. Nary a hiccup. My personal guns I've done the same thing of 350+ with the BOLTS and never had an issue. Of course the barrels get cleaned every 80-1000 rounds or so. These are BHW barrels that I am referring to and they are so smooth they just don;t foul. If I were worried about the high shot count and my bolt I would run a chromed or Boron BCG unit. They will wipe down with a cloth and as long as you keep them oiled you will never have an issue. The railed upper shoots like nothing I've ever felt before. It almost seems to short stroke and you just don't get the effect of it moving back and forth. I have shot lots of matches with guys running piston uppers and while they ran fine the guys all said they were giving up some accuracy and the guns seem louder than a DI type. I find it hard to believe that hanging all that extra stuff on the barrel cannot be a negative influence on the accuracy. I am super interested to see how you do on the groups and in the field. The AR's get a good workout from me on PD's and I find many to be stellar in accuracy and application. Welcome to the board. Greg
|
|
|
Post by ducksmasher on Jul 15, 2012 17:55:46 GMT -8
Glshooter correct me if I'm wrong here. I shouldn't worry to much about cleaning unless I feel the gun starting to act up. As for running a railed upper with a piston it's possible that I may Not to have the accuracy problem as a standard upper? Glshooter what optics do you run on your gun for p-dogs to shoot 3-400 yards?
|
|
|
Post by GLSHOOTER on Jul 16, 2012 12:56:51 GMT -8
Glshooter correct me if I'm wrong here. I shouldn't worry to much about cleaning unless I feel the gun starting to act up. As for running a railed upper with a piston it's possible that It's possible Not to have the accuracy problem as a standard upper? Glshooter what optics do you run on your gun for p-dogs to shoot 3-400 yards? I think the cleaning is more focused on the barrels. A quick wipe down with a cloth or even a blast of brake cleaner and some new FP 10 slathered on will handle it for you on a DI expedition if you are ultra-concerned. Myself? I just wipe 'em down and re-oil.. I think the railed upper will smooth it out but I truly believe the piston set up will disturb the harmonics. I haven't personally tried one and it is not irreversible if you go that route so a test drive might be very educational for all of us. If you do it would be interesting if you could do some DI groups and some GPU groups with the same loadings. You might be able to work around the harmonics but I believe it will be a challenge. Optics at 300-400 on the Pd's are easy. I use Nikon Buckmaster SF scopes. 4.5X14 and 6X18. The little ones are mil-dot as they didn't make them in the 6X18's when I bought them. The MD's really help on those non-dialed shots. All run target turrets. I also will use 4.5X14 Leupolds for the deed. I find that either s good out to 400. At 500 the 18 does make a difference though. The PD's here are SMALL and I want all I can get to see their beady little eyes peeking at me over the hole entrance. Greg
|
|
|
Post by ducksmasher on Jul 16, 2012 15:59:48 GMT -8
I will in deed do a accuracy comparison dI vs piston. That is when the doc lets me do more than sit and lay in the bed. Back surgery comes with great limitations. Hopefully some time end of August first September hopefully. The up side is I have plenty of time to collect parts for my next build. I want something for competition I found a group near by that looks to hae a lot of fun. So I'm for a new challenge
Thanks for reply's
|
|
|
Post by GLSHOOTER on Jul 16, 2012 17:00:26 GMT -8
I will in deed do a accuracy comparison dI vs piston. That is when the doc lets me do more than sit and lay in the bed. Back surgery comes with great limitations. Hopefully some time end of August first September hopefully. The up side is I have plenty of time to collect parts for my next build. I want something for competition I found a group near by that looks to hae a lot of fun. So I'm for a new challenge Thanks for reply's The old Bad Back excuse? I resemble that!! I didn't have surgery but recovery is SLOW. Don't push it and the longer you plan the nicer the options you will pick!! Greg
|
|
|
Post by ducksmasher on Jul 17, 2012 18:25:25 GMT -8
It's the best I could come up with! Im definantly not pushing it. Hell i cant drive untill Aug. 8 th. You are right about taking your time. It took me almost 8 months to build this one.
|
|
texcl
Junior Member
Posts: 19
|
Post by texcl on Jan 6, 2013 9:02:10 GMT -8
It would be interesting to build the rifle as a DI gun then a piston set up and see if there is a real loss in accuracy. As far as reliabilty, with modern ammo these rifle dont have too many reliabilty problems. I'm the primary firearms instructor and armorer for a group of guys in a federal agency. Once I received a group of brand new M4a1's from colt and I proceeded to equip them with Acogs and run them through the 200 round break in before issuing them. I held one rifle back and used this one for qualifications and training. I never cleaned the weapon or oiled it for over 1000 rounds probably closer to 2000 much of which was full auto. The rifle never had a hiccup. I have seen other rifles come out of the field that were oviously abused with heavy fouling that was turning green, and they would function fine. Most jams I encounter are caused by user error and damaged magazines. Of course lots of dirt introduced into the action will jam her up but that goes with any rifle.
|
|
dr69er
Senior Member
Protect the US Consitution & the American Way.
Posts: 222
|
Post by dr69er on Jan 6, 2013 18:34:12 GMT -8
I think the railed BHW uppers will help stabilize the piston system and thus you will have less variation in accuracy using the BHW system...Good Luck,YMMV .
|
|
|
Post by Babaganoush on Mar 27, 2013 21:51:39 GMT -8
Just to bump this thread -
Ducksmasher, I am curious if you ever got around to doing the GPU vs. DI comparison with your BHW barrel...
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 28, 2013 8:26:38 GMT -8
The M1A is a piston system but it was designed from scratch to be that way. When you have a piston system in an AR you are introducing new force vectors that do not exist in the DI design. I think some of the side effects of this fundamental change can be mitigated by focusing in a few points. The weakest point in the AR system is the upper receiver thread for the barrel nut. No matter how beefed up an upper or even monolitic designs are the dimensions on this area are the same, they have to be. So often a larger section in barrel is introduced thinking will reduce the flex as a result of the torque forces but it does nothing in that critical barrel / receiver are and if that union is not strengthened. In the end the AR is not a truly 100% free float system like many bolt actions as the same barrel nut is also the support for the handguard/rail system.
There are many theories but a none that can be identified as one single measurable solution. One simple thing though might be the use of a sturdy barrel nut that at the same it supports the rail it is bonded or bridged to the upper receiver. Never bridge the gap with part of the scope mount. That is a bad idea for other reasons anyway. But, this might end up being stronger than a monolithic upper with a smaller nut that does't do anything extra to support the threads from the upper.
The elimination of any carrier tilt, although marginally might also assist if it will 'smooth' the firing full cycle.
for long range work and out of all the versatility and options a piston might provide the most attractive might be a cancel function. In other words stop the cycling all together just like the M1A has. The adams comes with 3 settings full open, suppressed and cancel.
But in the end when it comes to extreme accuracy it seems to me the Army's are going DI with their advanced DMR/Sniper systems like knights (US) or the LMT (UK).
I have 3 piston systems but all my long range ARs are DI.
|
|