bone head move. anyone else seen this?

[Lloyd Smale]

Loaded about 500 (I know load a few and test before doing a bunch) 300 bo with a rcbs 130 pointed gas check bullet. Havent been able to do any real accuracy testing but they seem to shoot about 3 inch off hand at 50 yards so there acceptable. Well almost. The snow finally melted and I found a whole bunch of gas checks half way to the target and found about 20 of the bullets. Every bit (or at least lots) of pc is missing on the bullet where it engaged the rifling. Now heres my theory on it. I had to flare the cases to get the bullets to seat without shaving so I used a lee factory crimp die and put a pretty good crimp on them. Im wondering it that crimp pealed the pc off the bullets and maybe the gas checks too. the bullets pass a smash test just fine. as a matter of fact they were out of two different colors and both passed the smash test. Never seen this before but then I haven't used pc at 2000 fps either. By the way the bullets were hard. cast out of 5050 monotype and ww. tested at about 22 on my hardness tester. So basically linotype. Bullets showed no sign of stripping through the rifling. All showed nice rifling marks on them. Loaded some more with no crimp, just straightening out the rim but theres not enough snow left to test them! By the way I did shoot about 200 of them out of that gun. Bore looked like it had just a tinge of leading but it wiped right out with a brass brush. really no harder to clean then if I would have used jacketed and I cant figure that part out either. Im sitting here with 500 more of them that is my own stupid fault. Youd think after near 50 years of this kind of mistakes id learn. but winter is long and boring and reloading passes the time.

[Winger Ed.]

Maybe some sort of contamination or not being cooked enough kept the powder coat from making a good bond.

If the PC wasn't bonded to the boolit, the gas check could slip off with it.

As good as a smash test is, the forces working on a boolit in flight might be a bit more severe.

[Conditor22]

Pictures would help

[RP]

I have done the same kind of thing before sitting in the shop on rainy days with nothing to do I start cranking out rounds that I feel are just fine to find out I have a issue. The last big mistake I made was a 50 cal ammo box full of loose 45 acp that were not seated deep enough to work in all my Autos. I just labeled the box for the guns that they would work in so kind of got lucky.

As far as the powder sticking and doing smash test I bake longer then needed yes I know 400 degrees for 10 mins after they gloss over but whats a few more mins at the end of the day. The oven is hot I getting another batch ready to load in the oven my timer goes off anything after that is bonus cook time.
There is several this seems to upset but my thinking is I have a full size oven and my trays hold a lot of bullets so that is a fair amount of mass to heat. Even if the skin temp reaches 400 with all the mass dropping the temp after that happens giving it extra time to level out is a plus for me. One less thing to worry about.

[Dragonheart]

Just speculation I would have to agree with Winger Ed about the PC not getting a full cure or contamination. A water drop to cool is a good way to get contaminated bullets.

I double coat rifle bullets using a partial cure for the first coat then seat my gas checks a bare alloy base then do a second coat at full cure. The check is crimped on then bonded with PC so it is not going to come off. It's more work, but what is a little extra time on a long cold winter?

[Ozark mike]

Probably should of cooked a little longer. my pc experience is on motorcycle frames and alike just steel. I know a lot of ppl using pc but seem like too much work to have all these hangups I'll stick to good ole lube I guess

[bmortell]

I would think its impossible for a crimp to make the gas check slip back cause its what's directly being pushed on by the powder

[popper]

PC still on the boolit but not in the groove? Larry G. had trouble with lino & GC too. I push pretty hard in 308 & no missing GC. For the boolit the GC shouldn't be below the 'shoulder' in BO. If PC not cured you get nasty in the bore. My guess the hard alloy causes the PC to rub off in the groove. Larry went to #2 to eliminate the GC loss, but IMHO it has something to do with the GC and alloy hardness. GC 'resize' the shank slightly and extra friction of the GC when shot 'pull' it off. Several have noted the shank is undersized on recovered cast. Pressure also 'softens' the alloy at the base. Try PC after installing GCs - will tend to glue them on.
I FCD the 308 & BO but not a hard crimp.

[RED BEAR]

Oh yes loaded 2000 shotgun shells and then realized they were to light to function in my auto. Well dust off the double or my pump.

[Lloyd Smale]

I cook at 420 for at least 20 minutes

I have done the same kind of thing before sitting in the shop on rainy days with nothing to do I start cranking out rounds that I feel are just fine to find out I have a issue. The last big mistake I made was a 50 cal ammo box full of loose 45 acp that were not seated deep enough to work in all my Autos. I just labeled the box for the guns that they would work in so kind of got lucky.

As far as the powder sticking and doing smash test I bake longer then needed yes I know 400 degrees for 10 mins after they gloss over but whats a few more mins at the end of the day. The oven is hot I getting another batch ready to load in the oven my timer goes off anything after that is bonus cook time.
There is several this seems to upset but my thinking is I have a full size oven and my trays hold a lot of bullets so that is a fair amount of mass to heat. Even if the skin temp reaches 400 with all the mass dropping the temp after that happens giving it extra time to level out is a plus for me. One less thing to worry about.

[Lloyd Smale]

I do pc after I install checks and the checks fit the shanks nice and tight. I first size and while installing checks then pc coat then size again after. Ive shot bullets with the pc paint done the same way and even gas checked in my 9s and 40s as fast as a 1100fps and have never had this problem but then there taper crimped . Recovered a bullets out of the same snow bank shot from them and they were fine. I guess what made me think crimp was if you look at a crimp from a lee crimp die it has those little divits in it. I guess too if I would have only had the bare spots on the bullets or the gas checks loose I might blame the bake time or checks not crimping on but somethings going on to have both issues.

PC still on the boolit but not in the groove? Larry G. had trouble with lino & GC too. I push pretty hard in 308 & no missing GC. For the boolit the GC shouldn't be below the 'shoulder' in BO. If PC not cured you get nasty in the bore. My guess the hard alloy causes the PC to rub off in the groove. Larry went to #2 to eliminate the GC loss, but IMHO it has something to do with the GC and alloy hardness. GC 'resize' the shank slightly and extra friction of the GC when shot 'pull' it off. Several have noted the shank is undersized on recovered cast. Pressure also 'softens' the alloy at the base. Try PC after installing GCs - will tend to glue them on.
I FCD the 308 & BO but not a hard crimp.

[Willbird]

The upside is you were not shooting over Crono and have a gas check smoke a skyscreen. Never done that myself but have seen pictures

[Lloyd Smale]

well I found two possible culprits. One was I didn't bother chamfering the inside of the case because I was going to flare anyway. Second is that the seating dept was a tad long. I had a couple rounds stick in the chamber. When I knocked them out I saw where the pc had been taken off by them being slammed into the rifling. I wonder if that bit of a start to flaking off the coating didn't act like sand paper on the rest of the bullet. Gas checks were from sage and they were the ones he makes and not gators so I wonder if the crimp he puts is different then gators or there not thick enough to crimp with a 309 die. They went on nice and tight though and I pc over them. They do seem to shoot though. I never got past 50 yards yet but there easily one inch at that range. Pretty impressed with the gun all around. Its just a 16 inch psa gun I built. Like I said ive only shot at 50 yards but I shot 125 ww, nos bts, sst's, and sierra pro hunters and with wc297, 110 and 4227. I don't think I had a group larger then one inch at 25 yards and the bts and ssts shot basically into one hole. They even could be said will both shoot a one hole group shooting them mixed. Gun sure seems to shoot about everything including cast to the same poa. Only group that was really different was the cast group and ww groups (and it didn't like feeding that bullet anyway) were about a inch away from the other groups but still shot great. I will have to try it at a 100 but my optic is a burris 3x prism sight and its not all that precise for a 100 yards.

[Willbird]

Only group that was really different was the cast group and ww groups (and it didn't like feeding that bullet anyway) were about a inch away from the other groups but still shot great. I will have to try it at a 100 but my optic is a burris 3x prism sight and its not all that precise for a 100 yards.

IMHO the precision level can be improved with target selection. I have had good results taking a black center and putting a white diamond in the center, a square rotated 45 degrees, and size the white so when you aim you get 4 TINY dots of white showing...the rest of the diamond obscured by the cross hairs. Then we just aim until those tiny portions of white appear. I used that kind of setup for scoped pistol shooting testing loads with 3x-4x scopes.

[Dragonheart]

I think a lot of problems & potential problems would end if all measured the bullet jump for every type of bullet they load for a particular barrel. It is just a good reloading practice that is easy and only needs to be done once for every bullet type. You might be amazed at the difference it can make in accuracy as well as feeding. It also takes the guesswork out of setting your seating die. This holds true for both rifles & handguns.

[Lloyd Smale]

Ya after pulling down about half of the over a 1000 goof ups I loaded I will say this. I wouldn't never have guessed how much different brands of brass vary in bullet tension when just flaring the top of the neck. It is a major difference, surely enough to cause accuracy problems. then the ones I did with an m die all pulled out smoother and with very consistant tension.

I think a lot of problems & potential problems would end if all measured the bullet jump for every type of bullet they load for a particular barrel. It is just a good reloading practice that is easy and only needs to be done once for every bullet type. You might be amazed at the difference it can make in accuracy as well as feeding. It also takes the guesswork out of setting your seating die. This holds true for both rifles & handguns.

[Dragonheart]

Ya after pulling down about half of the over a 1000 goof ups I loaded I will say this. I wouldn't never have guessed how much different brands of brass vary in bullet tension when just flaring the top of the neck. It is a major difference, surely enough to cause accuracy problems. then the ones I did with an m die all pulled out smoother and with very consistant tension.

Yes, if you are shooting for accuracy the case make a world of difference in consistency and without consistency there is no accuracy. Many don't think so, but his applies equally to handgun as well as rifle. At my age I get absolutely no excitement in hearing my loads go bang, but I do get excited when I see the bullets go through the same hole. If I am going to handload, I load for accuracy. I know trying to make an accurate load takes more time just as my trying to make the best cast bullet, but to me accuracy is everything; if not for accuracy why not just buy fireworks.

I know this is just basic, but could your gas checks be too large and not getting a good crimp?

[sundog]

My complaint with two different 300 BO barrels I've tested recently is no throat. At the end of the chamber the rifling starts very abruptly - not what I would consider ideal for cast. It also makes difficult to fit a PC'd boolit.

[Dragonheart]

My complaint with two different 300 BO barrels I've tested recently is no throat. At the end of the chamber the rifling starts very abruptly - not what I would consider ideal for cast. It also makes difficult to fit a PC'd boolit.

Short of reaming the chamber I would check using an OAL gauge made for that purpose. The cheap way out is to take a sized and cut to length case and with a dremel make a couple of cuts down the mouth of the case so a bullet can just be started into the case mouth, then push the case into the chamber fully. Remove it and tells you basically where the bullets hits the lands.
Chamber throats and the size is important as this determines whether or not the bullet enters the barrel straight of at a cant. If it is really short loading heaver bulets is going to be a problem, but you probably already know that.

[Lloyd Smale]

yup I found that out fast when I had a load that ran perfect in the gun then with all the pc problems I had decided to put another coat on some of the bullets. Every one of them would stick in the chamber. Also have some 130 round noses that wont run at all. Either then jam into the rifling or if seated deap enough to avoid that slam into the forcing cone when fed from the mag. Actually a kind of small window for bullet choices that really work well in them. All could be fixed if the cut there chambers deeper. Im not worried about bullet jump. this isn't a bench rest gun its a battle rifle and loose tolerance are allways better in a battle gun. Heck even weatherbys with there longer them most bullet jump have shot great for me.

My complaint with two different 300 BO barrels I've tested recently is no throat. At the end of the chamber the rifling starts very abruptly - not what I would consider ideal for cast. It also makes difficult to fit a PC'd boolit.