Accuracy Bayou Bullet vs Jacketed in 9mm

[chiltech500]

LongdayJake, I'm wondering if leading occurs in a Springfield 9mm 1911 barrel because velocity is inadequate for the LSWC with the BN of 18 that I'm using?

I've had to crimp tighter to plunk the rounds for this barrel around .365.

 

[longdayjake]

Could be a few reasons. Your barrel is likely one that has a little larger bore. The biggest reason people get lead fouling is because hot gas escapes around the base of the bullet and "gas cuts" the lead. A lot of companies make their bullets really really hard to try to make up for that. Some say it works and other say it just makes for much harder lead stuck in your barrel. 18 has kinda become the go to hardness because it is still soft enough to obturate in the barrel and hard enough to resist leading caused by abrasion. Also, if you are shooting it too slow, it may not have enough pressure to obturate enough to fill any gaps in the barrel.

But to answer your question, 18 will probably work well in your gun so long as it is sized properly for your barrel. You may have heard the term "slug your barrel." Well, basically what you do is shove an oversize lead bullet through your barrel and measure the diameter of it when it comes out the other side. That will give you a better idea of the size of bullet you need. There are a lot of guys out there that know more about shooting lead than I do so you may want to ask around for more info on why you are getting fouling. I'm still pretty new at shooting lead and most of what I have shot has been powder coated. I am currently working on coming up with a method to mass produce coated bullets. It is much harder to do in bulk than you might think. So, until I get a perfect product out there, we will only be able to offer the lubed lead.

 

[longdayjake]

Actually, you may also be resizing the bullets too small by using a heavy crimp. In fact, that is the first thing I would probably try doing differently. If you are having to make the bullet smaller to "plunk" in the chamber you are probably making it too small to fill the bore. What size are the bullets you are loading?

 

[LiveLife]

Take apart a loaded round and measure the diameter. If it is less than the diameter it started out with, then you are decreasing the size of the bullet which will contribute to the leading problem, which is probably affecting your accuracy issue.

As long as you are leading your barrel, your accuracy issue won't be resolved by simply changing reloading variables like powder/charge, OAL, etc. If you are trying to develop an accurate "bullseye match" like load with lighter powder charges, you would need to resolve the leading issue first.

Good thing you got some JHP bullets on its way from RMR along with Berry's hollow base plated bullets to verify the accuracy of your barrel as you may not be able to readily resolve the leading issue.

 

[Jim Watson]

I think too much is being made of rifling twist rate in common pistol calibers.
There has been good accuracy reported for all available rates in well fitted barrels.
The European 250mm/10in standard might not be the best for lead bullets, but good work has still been done with them.
The search for a cure to inaccuracy in the S&W Plastic M&P is barking up the wrong twist rate tree. Hilton Yam's aftermarket and revised production barrels are doing better because they fit better, not because they have changed the twist rate. To something he could not be bothered to measure and they could not be bothered to tell him. Hmm.

 

[LiveLife]

Jim, I agree. Looking at the barrel twist rate at this point is putting the cart before the horse.

I really think the OP should give the load development of jacketed and hollow base plated bullets a "proper" chance before looking at other aspects of accuracy.

And I do hope the OP gets all the lead out of the barrel before commencing the range test of jacketed/plated bullets. (just kidding)

 

[chiltech500]

LOL BDS. Received my RMR JHP's Saturday. They are in very good shape visually and would have no problem with them as an alternative to new JHP's.

I don't know which manufact. these are, they're a bit shorter and the nose is more rounded than Hornaday's 124gr JHP. I'm eager to give them a try.

I recently tightened the crimp for the lead bullets to plunk test better. With a lighter crimp they were a tad high in that I had to press on them with my finger to have the edge even with the barrel's edge.

I have lots of rounds to deconstruct and measure, and was never that comfortable with crimping tighter because it's against the conventional wisdom.

 

[LiveLife]

Although RMR doesn't post that information, chances are likely they are from major manufacturers like Federal, Remington, Speer, Winchester, etc.

 

[longdayjake]

Which hp did you buy? I am guessing it was the 115 hp? We got about 100k of them a while back. Most of what we get from our suppliers comes from Federal so it is pretty safe to say that they came from there. However, the pullers also have contracts with border patrol and various police agencies that sieze ammo that could be from any manufacturer.

 

[chiltech500]

124 gr.

 

[chiltech500]

Plated and Jacketed bullets suggested earlier in this thread by bds are being tested with Titegroup powder, vs a token comparison to lead which really had not been working out well in prior accuracy testing.

124 gr target hollow point (THP) plated bullet by Berrys, OAL 1.095 with crimp of .377, Titegroup 4.0.

124 gr pulled JHP's from a major manufacturer, OAL 1.095 with crimp .376, Titegroup 4.0.

125 gr LSWC, OAL 1.095, crimp .377 with Titegroup 3.7.

Shot from a Hyskore rest, the 124g Berrys THP was the most accurate of the three. The best group was from the Berrys , about 1 3/4". Repeated that test twice more and the groups were not as good.

The next test is upping the powder for both jacketed and plated to 4.2 gr of Titegroup and shortening the OAL of the RPR pulled JHP's to 1.075.

The 124 gr JHP's are shorter than the 124 gr THP's and to have better comparison considering load bearing surface the JHP's needed to be sunk a bit lower. (if memory serves the difference in length is about .050, will verify with next tests data).