MidLife

Just curious?
I have been shooting about three years, and noticed, that those full metal jacket bulk buy ammo are great for plinking, but, the accuracy could be all over the place. Trade out that FMJ for lead SWCs (factory) and/or and personal hand/reloads, and the accuracy improves, much so.
Is this a indication that a softer lead bullet is engaging the rifling and spinning to the target and essentially more accurate that a harder projectile (FMJ) that receives "less" rifiling effect?
It is kind of interesting that a "clean, smooth, highly polished or refined" full metal jacket bullet is WAY so much innaccurate when up against a soft, lead bullet. It must be the engagement of the rifiling of the barrel. I cannot see any other motivating factor.

krwada

It depends; What are you shooting? I am assuming that it is some kind of pistol? Lead bullets do not do so well with modern rifles. That is because the muzzle velocity of modern rifles will strip the lead as it goes down the barrel.

Nick0410

I would think that the lead gets squeezed into the barrel more for a better fit? Probably helps with more uniform gasses escaping around the crown but I couldnt tell you for sure, I only loaded a few hundred FMJ and mostly reload plated. Even Hornady V/Z Max are supposed to have a thin jacket along with Speers are supposed to be plated also so little/no jacket helps with a better fit?

krwada

You said bulk buy ammo vs lead handloads. That pretty much answers it right there. Of coruse the lead hand loads will perform much better. The bulk ammo tolerances are just not that good ... especially the cheap stuff!

429421Cowboy

For one thing lead will fit the bore better, and expand a bit when it hits the forcing cone. Also, lead boolits are usually larger as a rule, than jacketed unless you are loading for a gun with super tight throats. This means a casd round will fit most barrels a bit better, even more so if you have slugged the bore and are shooting properly sized boolits for the gun. The more i learn about cast, the less i like jacketed!

Dozer02

It's been said before, bare lead bullets conform to the forcing cone/barrels rifling much better than standard "one size fits all" factory jacketed bullets. It's like they're force molded to each specific weapons dimentions just after the trigger is pulled so in most handguns the accuracy will be more consistant. This is certainly not the case with rifles though, the velocities/pressures & temperatures are far too high to produce the same consistant effects that the shorter barreled pistols display.

noylj

FWIW, the order of accuracy, in general that I have found, for pistol bullets is:
1) JHP
2) L-HBWC
3) L-SWC
4) FMJ-FP
5) L-CFP
6) FMJ-RN
7) L-RN
8) Thin plated bullets of ANY design
I haven't fired a RN is about 25 years and see no reason to ever again.
Then, I find that most "inexpensive" FMJ bullets are really plated and I have NEVER had any success with plated bullets.
Finally, your gun may like bullets that mine don't, so you need to find what your gun likes and not worry about what I think my guns like.

GP100man

Here`s is what an old Bullseye shooter explained to me .

Now remember we`re probably talkin 35-40 yrs ago of the bullet making industry.

Here goes ,the difference is caused by a root problem in the copper jacket drawing process asin the jackets are thicker/thinner (if only by thousandths & within the same jacket) & it allows a different bite (deeper/shallower at the thicker/thinner sides) thus the uncontrollable inconsistentcys of accurcy !Leaving the muzzle square but 1 sided.

This came from a fellow caster that indexed his brass so he could index the parting line of his boolit mold to the throat/forcingcone of his K-32 & K-38

I had no basis to argue & certainly not with his results on targets with both jacketed & lead.

With this said I have found different thickness between brands , at least there was 15yrs ago !

Snobal

I just started reloading in the 60's.

Anyway, I have always found that my "home-made" cast bullets produced better groups (and more consistent standard deviations across the chronograph) that "store bought" jacked bullets in hand guns.

I would not invest the time and effort in casting bullets for Bullseye Matches if I could find any "store-bought" bullets that shot groups at tight as my bullets.

In rifles, jacketed bullets rule (but below 2,000 fps, cast bullets do just as well).

JMHO - YRMV

brimic

Bingo!

One thing to look at is the bearing surface of each bullet- the length of the bullet that engages the rifling completely.
Any pistol bullet that is more or less a cylinder shape is going to have more bearing surface than something that is more of a 'bullet shape.'

Your wadcutters, SWCs, and even jacketed hollow points are going to have a lot more bearing surface than something that leaves a large amount of its mass sticking out like a RN.

punkinlobber

Lead obturates and jacketed bullets rarely do.

laidlerj

I had the same issue with an old Spanish-made .45 ACP pistol I got in trade. Unlike my other .45 ACP pistols, it wouldn't shoot FMJ or even single-loaded jacketed SWC bullets worth a darn, no matter if they were cheap bulk ammo, match-grade ammo or quality hand loads. However, when I fired my 200 gr cast lead SWC practice reloads in it, it grouped much better (remember, this was a Spanish 1911 clone, so it wasn't a tack driver).

I managed to retrieve a jacketed bullet from the berm and I noted that the rifling hadn't engraved very deeply at all and appeared "blurred" or "smeared". I slugged the barrel and found that it was a tad oversized; enough so that the jacketed bullets wouldn't get a good "bite". The cast lead bullets - even the hard cast ones I reloaded - would obturate enough to grab the rifling well.

The original poster doesn't mention if this was a problem with just one gun or with all of them or what caliber or action type, so it's hard to know if an oversize bore is the problem. We also don't know how big the difference was between the jacketed and lead bullets, so it's possible that what's described is just the difference between indifferently manufactured FMJ ammo and quality ammo.

Or it could be that the gun(s) is just "happier" with certain loads and not so "happy" with the bulk FMJ ammo. I had (past tense - I sold it) a Taurus pistol (Beretta 92 clone) that shot the Winchester white box 9mm FMJ's with "minute of miscreant" accuracy (1 foot at 25 yards from a sandbag rest), but could group 124 gr FMJ's just fine - still not a tack-driver, but could hit the broad side of a barn from across the pasture.

Jim

bhefley59

The four main pistol shells I load for are 9mm , 38-357 , 40 cal , 45 acp. I switched to Berry's plated bullets years ago with the exception of some Missouri Bullet co. 230gr LRN 45's . I think the plated bullets are very accurate for the type of shooting I enjoy "USPSA matches" . From 20 to 50 ft I can shoot a 1.5" to 2" group with a rest, 3" to 4" without . My SR1911 likes the LRN just as much as the plated can not tell much difference except the LRN do lead the barrel some .
For my rifles I use mainly Sierra Bullets , the factory is just down the road and you can buy bulk at the store. They are factory seconds so you need to weigh them and look close but most are good .

terry_p

Another possibility may be that loads for lead typically aren't as hot as for jacketed and maybe you handgun likes less powder.

MidLife

Not a "problem, just noticed how far better the groups were with the lead SWCs.

The gun is a GP100 357 magnum 4.20" barrel.