Groups opening way up when the barrel is fouled, 20 prac +update+

204 AR

204 AR

Well-known member
Ok I know most good barrels shoot better when clean, but this is the most extreme case I've come across. The weird thing is the barrel isn't that fouled, certainly not with copper. H335 is a dirty powder, I've just never noticed it this bad before.

BHW barrel, H335 pushing 40 gr bergers. Almost one hole at 100, and hovering right around an inch at 200, prone off of shooting sticks. After 20 rounds or so 200 yard groups go over 2", and it seems poi drops lower. Scrub the barrel with a few patches and nylon brush strokes to get powder residue out and it's back to shooting good. Even the fowler group is tight.

Just surprised, and wonder if another powder would yield longer good results. Any thoughts?
 
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Give benchmark a try. Or even h322. I run benchmark in my 20pr from WOA. I will agree that h335 is a very dirty powder. But you might be able to change primers and get better results. I run h335 in the 223's and have not had any real issues with accuracy. I'm using Remington 7.5's to set everything off and not much over 24.5 grains with the benchmark and h335. But under 25gr in both. running 35gr bergers with the 20 and 55gr NBT in the 223.
 
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I have a 1966 vintage Win M70 in 30-06 that was my Dad's. To say this gun is a copper miner is being kind.

When the barrel is squeaky clean, it needs 2 shots to foul before it shoots good. It will give about 3/4" groups at 100yds up to about 21-22 shots, then the accuracy goes away. Deep clean with Wipeout, shoot 2 foulers, and accuracy comes back.

The 1st shot when clean usually misses the 100yd target, while the 2nd shot is somewhere on paper.

I'm tempted to try Tubb's Final Finish, or even hand lap the barrel, but it does shot nicely up to 21-22 shots. My current solution is to just not shoot it much, just a few times during hte year then elk hunt with it. I have plenty of other rifles to use.
 
That's what is strange, this barrel is smooth. And it'd not copper causing the problem. I've just never had powder fouling cause an issue that I can remember that was this obvious and dramatic.
 
How fast of a load is this one? I've seen before on low pressure loads that fouling builds up quick. Just a shot in the dark...
 
I'd try benchmark and maybe even moly coating.... But honestly it's likely that barrel is just a rough one and drags copper. Not saying it's a bad barrel, just maybe not as smooth as some.

Benchmark sure runs clean, I love it.
 
If mine shot that good with H335, and got groups as described. I would most likely clean it after 20 Coyotes and call it good. Off of sticks? I would not complain. lol
 
Originally Posted By: pahntr760How fast of a load is this one? I've seen before on low pressure loads that fouling builds up quick. Just a shot in the dark...

Yeah I thought that also. The 40's are scooting along at 3700 fps. I don't think they are hot, but not exactly mild. I hate working up any higher in the winter with a temp sensitive powder.
 
Originally Posted By: Orneryolfart357If mine shot that good with H335, and got groups as described. I would most likely clean it after 20 Coyotes and call it good. Off of sticks? I would not complain. lol

Roger that, that's the plan for now. But I need a good pdog load also. I had a little benchmark but didn't get good results. I might try 8208. Tac also looked promising I might give that a quick try.

I wish I could find 20 coyotes lol. Been a slow year.
 
Originally Posted By: 204 AROriginally Posted By: pahntr760How fast of a load is this one? I've seen before on low pressure loads that fouling builds up quick. Just a shot in the dark...

Yeah I thought that also. The 40's are scooting along at 3700 fps. I don't think they are hot, but not exactly mild. I hate working up any higher in the winter with a temp sensitive powder.

Worth a try. It seems that the pressure must be on the low end due to the excessive powder fouling. Another powder may be worth a try as well...let us know after you play some more.
 
3700 is not unreasonable. I've never shot H335 in mine because of the heat. I'd try some Benchmark and some 7 1/2 primes. My load work ups are usually done at 90+.so that eliminates some powders to start with.


Greg
 
Update from today. I took data from the 204 book using imr 8208 so I could try it. Dropped 2 grains from max 204 to use as max for the practical. First I cleaned the barrel using Boretech eliminator. Rifle had been fired 7 times since the last cleaning. I got a lot of copper out of it pretty quickly. At first the patches looked dark like powder fouling but after they dried I could tell it was mostly copper. I think that is my problem after all. Interestingly my 204 copper fouls badly using h335 also. Hmm starting to notice a trend. But, it also happens to be my fastest cartridge, so...?

Here's the test results:




I cleaned after 15 rounds, these were all 8208 and 40 gr vmax. I definitely got less fouling out this time. But I did change both the bullet and the powder, so not sure which one it is yet. Now that I think about it I didn't notice much copper fouling in my load tests until I started using the bergers. So, more testing is in order still.

At any rate I started at 24.5 and worked up in .3 gr increments. At 25.7 ejector swipes were getting pretty noticeable and accuracy was bad, that's the 2 bad groups on the second target. I went back to 24.8 and loaded 5 rounds and that's the good group on the second target. No idea on speed as it's snowing and my crony is old and not too reliable. But both groups with 24.8 measure just under .6" so not too bad for windy snowy conditions and me just coming off the night shift lol. I think I'll load up 20 or so and see if it holds together.
 
Looks like you're onto something. Never saw a BHW barrel that was a copper miner. But I havent been around too many of the smaller bore dia rifles.

Good deal...keep updating as you play some more.
 
Ya I've had a few BHW barrels, this one might be the most accurate but also apparently rough. Of course I would expect a fast 20 to foul worse than a 6x45 or 308. But my 243 didn't seem to foul bad either. It's too cold/windy to shoot today so I'm going to clean it good and Bore Coat it. I will let you know the results. Hopefully I don't ruin the accuracy.
 
Originally Posted By: 204 ARYa I've had a few BHW barrels, this one might be the most accurate but also apparently rough.

That is the most accurate? I just ordered a BHW barrel in 20 Practical for an AR15. Got me wondering if I should have went with a Shilen or Pacnor now?
 
Have you read the whole post or just look at all the groups on that load work up? If you notice they are all different powder weights except the two groups at 24.8 gr which measure right at .6". Conditions were bad with wind and snow or they might have been even better.

Fear not, if you get the load right it will shoot. My best load with H335 and 40 gr bergers bugholes with a clean barrel. This post was about fouling and losing accuracy, not about lack of accuracy in general. And I just finished Bore Coating this barrel so fouling should be all but eliminated hopefully.
 
Originally Posted By: CoyotejunkiOriginally Posted By: 204 ARYa I've had a few BHW barrels, this one might be the most accurate but also apparently rough.

That is the most accurate? I just ordered a BHW barrel in 20 Practical for an AR15. Got me wondering if I should have went with a Shilen or Pacnor now?

I've never seen a BHW barrel that didn't shoot well. And if it doesn't, I'm sure they'd take care of you on it.
 
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