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Post by mosigdude on Mar 1, 2015 11:02:42 GMT -8
Thanks. How was the pressure with the IMR 4198? All our published loads are 56,000 PSI or less Are you referring to the test loads posted by GLSHOOTER or are there other loads listed somewhere?
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Post by cpct on Mar 1, 2015 12:08:20 GMT -8
That's why I posed my original question. I know what I've settled on, in theory, but without published data, this is going to get very expensive. Can't even guess at the hundreds I spent on my 6x45 development before hitting the sweetheart load for my rifle.
Glenn, Can you describe your pressure signs, and, what did you see at lower charges, say 27 grains of RL7?
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Post by geepee3 on Mar 1, 2015 12:24:03 GMT -8
Glenn, Can you describe your pressure signs, and, what did you see at lower charges, say 27 grains of RL7? Flattened primers, some cratering. Brass stamping into ejector hole and extractor slot. The 27 grains of RL-7 gave the same results, but gave signs at a slightly lower velocity... Avg. 2440 fps. I'm thinking it's the mid length gas system because the guys with 16" carbine gas systems are going full steam ahead. Glenn
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Post by GLSHOOTER on Mar 1, 2015 13:59:47 GMT -8
Let’s get the table set.
This is a wildcat. General powder choices will be used by any of the rifles in the same chambering. Variation in case capacity, from brass, is an issue, as is the use of different primers or even neck tension can make a huge impact on results. The load data that I have posted up is all 56,000 or less. We test loads and don't post anything that doesn't indicate it is safe. We have shot far hotter loads than we would ever put out without issue. Nothing says you can't cheat but at some point you do get caught. We're not going to let you crater based on unsafe data.
The A-30 is a piece of cake to work with. Grab any 7.62X39 data and use that as your starting load. We run higher pressures than the 39 and have greater case capacity. Belt and suspenders. The powders work very well for this one. Venture out into the powders being used in the 6 PPC and you get a few more. Once again we have better capacity and the expansion ratio really helps in dropping pressures. I spend an inordinate amount of time looking over the net for similar cases in design or capacity and use those as a minor yard stick. Derivatives of cases, ala wildcatting, really let you pick and choose components based on the parent case and its' behavior along with other variants of similar design.
Load development on a budget means three shot groups at each load level observing for swipes, craters and mangled rims. I have, at last count, thirteen BHW chamberings with some of them being multiple barrel lengths from 16"-26". Development for a good load and expense has NEVER exceeded more than one pound of powder and 200 bullets. Most load development is done in one box of bullets and a half pound of powder. I use a box of bullets because I want 100 pieces of brass formed on the first trip. It's not unusual for me to find THE LOAD in fifty shots. I'll use on bullet and as many as four powders on my hunt. I shoot 90% of my rounds through a chronograph. I never just shoot for speed or just for function. I want to get speed and accuracy at the same time and function of the rifle is a by-product of that process. All data is done up in Excel regarding COL, case. primer, temperature, neck tension and atmospherics. All shot targets are kept for record along with pertinent speed and load data.
There are times when the speeds are way down on the first tier and I'll skip my normal two group test. Most times I find the barrels like it hot just like I do. I am watching for speeds that are too god to be true and if that happens I stop right there. A 4350 FPS 17-223 will teach you PDQ to hold the horses..quickly. You must realize that XXX will only go so fast and if it does what you need as in kill paper or warm targets that's all you need to worry about. Burning out a barrel, no matter how good, searching for a one hole load isn't going to work quite simply. We can get close and get those little ones frequently but none of these will do a bug hole every group. The bolt guns will come close but that's a different animal than an AR with all the wham bam thank you mam's going on.
Now let's see some targets................
Greg
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Post by cpct on Mar 1, 2015 14:18:38 GMT -8
Well put Greg. I'm ordering up 100 Barnes 130's and just picked up a pound of RL7. My plan is to shoot in the 27-28.5 grain range on an 18" mid gas barrel. I can't see where that would cause any pressure issues, especially with a BHW barrel. I run a VERY compressed load of 8208 in my 6x45 with 85 grain Barnes TSX and have no pressure signs at all. If I get 1' groups at 100, I'm happy. It's a hunting load, not a bench load. Most of the hogs I've shot have been at 150 yards or less....one of them at 5 feet. Darn thing came out of nowhere!!! Anyways, thanks for all your help and patience. I'll post up my targets as soon as I get my barrel.......8-12 weeks....hoping for the 8!!! I have a coastal hog hunt and REALLY want to post something special!!!
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Post by geepee3 on Mar 1, 2015 15:01:19 GMT -8
Well I don't know what to say about the issues I am having. Greg I have had the rifle out a few times and keep running into a brick wall. Right now this caliber has me stymied, and I need a break. So I will be shooting my 6X45 mm rifle next time out. Any load help on the A-30 would be appreciated.
Glenn
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Post by GLSHOOTER on Mar 1, 2015 15:45:03 GMT -8
Any recommendations for a mid length gas system. I have tried the four powders R. Johnson recommended. The BHW barrel is an 18" mid length. Once over 2460 fps with a 123 or 125 grain projectile I start getting pressure signs after the first two shots of a string of five. I was hoping to be able to get over 2500 fps with this barrel, but so far no go. Also getting pressure signs with 110 grain Nosler with 29 grains of RL-7 powder. Again after two shots, the rest show signs. Any help will be appreciated. Glenn What are your shoildrr numbers with a Hornady HS gauge on a fired vs a sized case.? What max is your OAL lenght with loaded rounds and various bullets. Now one other thing. What is the depth of your bolt face from the top of the lugs to the bolt face? Greg
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Post by cpct on Mar 1, 2015 15:54:13 GMT -8
So you think he might be jamming the lands, Greg? Neck tension and crimping....especially overcrimping could cause his symptoms, too. Just a thought.
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Post by GLSHOOTER on Mar 1, 2015 16:18:27 GMT -8
So you think he might be jamming the lands, Greg? Neck tension and crimping....especially overcrimping could cause his symptoms, too. Just a thought. No I don't. The numbers will give some clues. Greg
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Post by geepee3 on Mar 1, 2015 17:07:40 GMT -8
What are your shoulder numbers with a Hornady HS gauge on a fired vs a sized case.? What max is your OAL lenght with loaded rounds and various bullets. Now one other thing. What is the depth of your bolt face from the top of the lugs to the bolt face? Greg Shoulder readings with Hornady gauge. Sized case for chamber -.003 for headspace for bolt, 1.349". Fired cases run between 1.356-1.361" with all the brass showing pressure signs in the 1.359"+ range. Using both SSA and FC brass. Overall length of cartridges, With Nosler 125 gr. ballistic tip, 2.295". Lapua 123 gr. FMJ, 2.190", Nosler 110 gr. Varmageddon, 2.275". Depth of bolt face from top of lugs, .123" Daniel Defense 6.8 SPC bolt. Hornady 30 Harrett dies used No Crimp!!!Edit; Primers used have been CCI BR-4 or Federal GM205MAR. Both are Match primers. Glenn
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Post by madcat on Mar 2, 2015 12:53:21 GMT -8
Just throwing in my 2 cents on your pressure signs. I am assuming you set your dies with the supplied gauge? Reason I'm asking is , its possible you might have the shoulder back a tiny bit to far and slamming the case. into the bolt face. If this is happening you could get some false indications of over pressure. I personally use CCI 41 primers which are a bit harder ,so I put more weight into imprinting signs on the case.
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Post by GLSHOOTER on Mar 2, 2015 14:12:52 GMT -8
Just throwing in my 2 cents on your pressure signs. I am assuming you set your dies with the supplied gauge? Reason I'm asking is , its possible you might have the shoulder back a tiny bit to far and slamming the case. into the bolt face. If this is happening you could get some false indications of over pressure. I personally use CCI 41 primers which are a bit harder ,so I put more weight into imprinting signs on the case. That's some good thinking there. Greg
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Post by geepee3 on Mar 2, 2015 16:04:14 GMT -8
Thank you for the input. Madcat you may be right. I have RCBS 6.8 SPC shell holders and the A-30 gauge they sent me will not seat in them. I will sand down the bottom hub of the gauge to fit the shell holder and go from there. Thanks Guys, I really appreciate the help.
Glenn
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Post by madcat on Mar 2, 2015 16:09:43 GMT -8
The gauge is not supposed to fit in the shell holder. It simply rest on the top of it. I know its odd but the groove around it means nothing. Just sit it in position and bring the die down to touch it and your done. From what I was told the groove is there to make it look like a bullet. I tried to put it in my hornady shell holder and it doesn't fit either. Be really bad if it did because the shoulder would be way off. I would highly recommend this gauge be remade with added length to fit a shell holder instead if on top. Might clear up the confusion.
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Post by geepee3 on Mar 2, 2015 16:47:13 GMT -8
With the gauge on top of the shell holder, my die will not fit down enough to resize the neck of even the fired cases or bump the shoulders. Greg sent me a PM and I am going to bring the shoulder up more to what he suggested.
Thanks again Madcat.
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