FMJ....?

[poline]

Many years ago, I had a fellow tell me that if you had a new gun, that you cared about, that the first 100rds thru it should be FMJ, to further cut and define the groves.
I'm wondering what the FORUM's thought on this is?

[Jimro]

Utter bull.

Jimro

[hk33ka1]

The question would be what would FMJ (they have a normal copper jacket) do different than say normal copper jacketed match or normal copper jacketed hunting bullets?

Lead may be a different story if the rifling for an older or replica firearm has something special about it.

[Jimro]

Nope, gilding metal is gilding metal, at least as far as gilding metal goes. The steel FMJ bullets don't do any bore any favors.

I've heard all sorts of theories about barrel break in over the years, this one is pure bunk.

Jimro

[TheDoubleDeuce]

I had a guy tell me to shave my front sight down to LOWER the point of impact.

I had a guy tell me if I used lacquered surplus ammo, my bolt WILL stick and I will NOT be able to get it open.

I had a guy tell me if I used modern 308 ammo, the rifle might explode.

And that was one day at the range with one Mosin Nagant. Point is, if it sounds fishy, take it with a grain of salt.

[poline]

I'm sure this was in reference to lead vs metal......FMJ, JHP etc.

[Hammerhead]

The steel FMJ bullets don't do any bore any favors.

Steel FMJ's???
You mean steel core?
I don't think the OP is talking about steel bullets.

[hk33ka1]

I meant to agree with Jimros first post above. Forgot to type the full normal copper jacket statement on each type listed.

[Jimro]

Steel FMJ's???
You mean steel core?
I don't think the OP is talking about steel bullets.

Some countries facing a copper shortage resorted to using mild steel jackets for wartime production. And I agree I don't think the OP is talking about steel bullets, but since FMJ is a title that doesn't mean "drawn gilding metal jacket over lead core" specifically I mentioned them.

As far as steel cored bullets, (like black tip 30-06 AP bullets) they are covered in gilding metal, and while the steel won't compress the way a lead core will, I have never found anyone who has noted a difference between steel and lead core bullets through the Garand in terms of barrel wear.

Jimro

[wogpotter]

I had a guy tell me if I used lacquered surplus ammo, my bolt WILL stick and I will NOT be able to get it open.

There is actually a grain of truth behind this. The details are a bit "off" though.

Some time back in the 1970's back in the U.K. there was a lot of either .303 Brit, or 7.62 NATO (I forget which, but am leaning towards the .303 Brit as I fired much more of it) That had a "shellacced" brass case. The "shellac" vaporised under heat & stress & resolidified immediately after firing & coated everything.

It was supposedly some lot destined for tropical jungles or something environmentally 'orrible. Several shooters got "sticky" bolts & very hard extraction after firing lots of rounds in matches. They didn't actually weld shut, but the operation was noticably stiffer & more ugly & cleaning the stuff out was an absolute bear!

For a while we all wiped our live ammo with meths (alcohol)-dampened rags just to dissolve the stuff before firing it.

[wogpotter]

Back on topic though.
Jacketed is jacketed, (unless you have that hideous old jacket material that would irrevocably plate to the bore). Gilding metal has been replaced with cupro-nickel & much better jacket materials nowadays.
Other than thinking the OP is referring to jacketed Vs cast bullets to sort of "fire lap" the bore it sounds like rubbish to me.

[Unclenick]

If you follow barrel break-in discussions (lots of controversy there) you discover that firing full power jacketed bullet loads can burnish a bore to reduce wire edges or other machined sharp spots a bit. Usually, for a rifle, firing just 10 to 20 rounds with complete cleaning between each round does all you can hope for, and that can cut down on copper fouling noticeably. Howa's distributor recommends you use Windex for the cleaning to remove all copper and hydrocarbon traces. The latter is so hydrocarbons don't burn off to build carbon up in the tool marks and other surface imperfections where it can interfere with burnishing and I infer they think it may play some role in encouraging heat walking. But a lot of pistol rounds don't develop enough pressure to deform a jacket down into the inside corners of the lands, so the value is a lot less certain in handgun loads; especially in the lowest pressure loads.

There are better ways to go about conditioning a bore for lead bullets. If you slug the bore and detect actual constrictions, fire lapping is the way to go. Well short of that, try wrapping a couple of patches around one-size-too-small bore brush, put Iosso Bore Cleaner (my favorite as it has no oil or hydrocarbons) or JB Bore compound on the outside and work it back and forth about 50 times (this is also what Varmint Al uses in place of break-in for rifle barrels, though he tries Flitz first and uses JB only if that doesn't work well enough). That will polish the bore surface enough to help. Ken Mollohan wrote up an inbetween method of shooting bullets down a bore with JB in it. It's the second article down, here.

[BoogieMan]

@Unclenick-I dont want to highjack the thread. BUT, I have a lightly pitted mauser. Would or could this compound fire polishing work in such a case? I am waiting for the JB bore polish to come in from Brownells.

[Unclenick]

It will help take the sharp edges off the pits, which should help prevent them from increasing metal fouling greatly. I would use only synthetic oil in such a bore (Mobil 1 or Slip 2000 Gun Oil for example) so traces that don't patch out before shooting don't burn off and leave extra carbon behind.

[reynolds357]

Jacketed as opposed to cast would be accurate.

[USMC EOD]

I have heard that a 1911 should be broken in with FMJ round nose ammo before moving on to JHP ammo. A 1911 that has not been broken in may not work well with something else like JHPs.

[Marco Califo]

I read somewhere, and I think it was G. Gordon Liddy's book "Will", re: FBI training, that the purpose of filing the front sight down was so that it would not hurt so much when someone took it away from you and inserted it in your rear because you were not really prepared to use it.
Of course, no one was really supposed to file their sight down. But, does your handgun shoot high?

[Jimro]

We should probably start a thread of "classic firearm myths."

Every time I had a crappy day I could read through it and laugh.

Jimro

[Bart B.]

We are already posting in a thread of "classic firearm myths." Here's another one:A 1911 should be broken in with FMJ round nose ammo before moving on to JHP ammo. A 1911 that has not been broken in may not work well with something else like JHPs. When I started shooting bullseye NRA pistol many years ago, a couple of Nat'l Champs and other record holders told me to not be like all those rifle shooters that think they have to break in their expensive match barrels before they'll shoot good. One's name was Don Hamilton who had just won the 1969 Nationals setting a record with his brand new barrels in both his M1911 wadcutter and hardball .45 ACP guns with brand spankin new barrels in 'em (so said Ken Johnson, the 'smith at the USN Small Arms Match Conditioning Unit that rebarreled those 1911's for him). That record stood for over 30 years. Regarding brand new barrels in handguns, he sometimes said: "Just shoot the darned things in matches when the rifling's brand new and accuracy's the best."

There were Nat'l Champs who didn't worry about having the best accuracy in their 3 pistols shooting 2700's in competition. SFC Bill Blankenship had his choice of three .38 AMU 1911's for his centerfire pistol at the Nationals in the early 1960's. Tested in a Broadway machine rest, one shot well under 2 inches, another about 2 inches and the third about 2-1/2 inches at 50 yards. He chose the least accurate of the three because it had the best trigger for his technique of shooting. He used that least accurate one to win the Nationals and set a centerfire record.