Gas checks on PC'd bullets

[Lloyd Smale]

yes I do realize theres a major difference between platted bullet and jacketed. I also know that plated like rainer sells do work. What I don't know is how pc bullets stand up to plated bullets in performance.

Loyd:

Berry's, Rainer, Xtreme, etc. all sell plated bullets, not jacketed bullets. There is quite a large difference, in both performance, and cost.

Just an FYI to others reading.

[noisewaterphd]

yes I do realize theres a major difference between platted bullet and jacketed. I also know that plated like rainer sells do work. What I don't know is how pc bullets stand up to plated bullets in performance.

In my opinion and experience, powder coated, or Hi-Tek coated bullets give far superior performance to plated bullets.

You can push a coated bullet much harder than you can a plated bullet.

[Lloyd Smale]

Ive pushed plated 357 bullets to 2500fps in my 356 with no problems and decent accuracy. Don't know how coated could do much better. From what ive found if you push a bullet over 2500fps for the most part accuracy goes to heck no matter what alloy your using. That kind of pressure plays heck on the integrity of your bullet and basically turns it into a blob of lead in the bore. Some call it bumping up bottom line I its a non issue to me anyway as 99 percent of my plated bullet shooting is with my Beowulf and 1800 is about as fast as you can run one in it and it is the only round I can see going though the hastle of coating. Anything else I have runs conventional cast just fine and there a lot less work. Only advantage to a coated or plated bullet in the beo comes from the fact its an ar and subject more to malfunctions due to fouling.

In my opinion and experience, powder coated, or Hi-Tek coated bullets give far superior performance to plated bullets.

You can push a coated bullet much harder than you can a plated bullet.

[noisewaterphd]

Ive pushed plated 357 bullets to 2500fps in my 356 with no problems and decent accuracy. Don't know how coated could do much better. From what ive found if you push a bullet over 2500fps for the most part accuracy goes to heck no matter what alloy your using. That kind of pressure plays heck on the integrity of your bullet and basically turns it into a blob of lead in the bore. Some call it bumping up bottom line I its a non issue to me anyway as 99 percent of my plated bullet shooting is with my Beowulf and 1800 is about as fast as you can run one in it and it is the only round I can see going though the hastle of coating. Anything else I have runs conventional cast just fine and there a lot less work. Only advantage to a coated or plated bullet in the beo comes from the fact its an ar and subject more to malfunctions due to fouling.

Well, i have never bothered to to try a plated rifle bullet. I wasn't even aware anyone made them.

I have multiple handgun calibers that can tear a plated bullet to shreds(including "heavy plated" offerings), where lubed or coated bullets will hold up just fine.

[Lloyd Smale]

ive never seen that problem using berry or reineer plated bullets in any of my guns.

Well, i have never bothered to to try a plated rifle bullet. I wasn't even aware anyone made them.

I have multiple handgun calibers that can tear a plated bullet to shreds(including "heavy plated" offerings), where lubed or coated bullets will hold up just fine.

[noisewaterphd]

ive never seen that problem using berry or reineer plated bullets in any of my guns.

Well then you just aren't trying hard enough

[Lloyd Smale]

the reineers shoot 1 1/4 inch for 5 shots at a 100 yards pushed to 1800 fps out of my Beowulf and have killed three deer and a pig so far. Id say 1800 fps and running through the action of an ar15 is a pretty telling test. ive shot proably 5k through that gun and I know my buddys beo proabably has seen twice that many. that and I inherited a box of a 1000 of them from a buddy who died for the 45acp and shot a whole year of ppc and practice with them with no problem.

[StuBach]

So not to be the stick in the mud but isn't this thread about Gas checks on PC'd bullets.

Don't really want to stop the conversation on everyones opinion about jackets vs plated vs PC but I think that was outside the scope of this thread. Maybe start another thread with a title to that regard and get additional conversation from more members?


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[jimb16]

I was wondering if a light coat of PC on the shank then curing with a GC in place would "cement" the GC in place before you PC the entire boolit. Then It could be sized afterwards?? Just thinking.....

[RP]

Yes you can use powder to glue the GC onto the bullet.

[Dragonheart]

Since I am now double coating rifle bullets to obtain a thicker jacket. My second coat is with the gas chek in place. Bothe coats are sprayed. Once cured the check definately becomes part of the bullet. I am still using some gas checks because I have several desirable rifle molds that their design requires gas checks.

[bazzer485]

Here's a question from a novice caster. With the double PC coating described here that increases the overall diameter by 8 thou. Do you start with a different sized casting die than that used for a "conventional " gas checked sized and lubed bullet? Or is your sizing swaging down your 8 thousands of a inch?


Interests include Fly Fishing, Archery, Shooting and many more. British Military Veteran.

[Dragonheart]

Here's a question from a novice caster. With the double PC coating described here that increases the overall diameter by 8 thou. Do you start with a different sized casting die than that used for a "conventional " gas checked sized and lubed bullet? Or is your sizing swaging down your 8 thousands of a inch?
Interests include Fly Fishing, Archery, Shooting and many more. British Military Veteran.

I am sizing down the bullets before coating. Presently I am working on 30/06 caliber. .308" is the smallest sizing die I have at the moment. Al at NOE Bullet Moulds said he will send me a .306" Bushing when he can. I am also nose sizing the particular bullet I am working with which is a NOE #HTC309-153 a 30 Cal.156 Gr. SP. This bullet is a no groove plain base bullet. I am also sizing between coats as this tends to work harden the polymer. I am looking to get a .003" thick coating from the substrate.

My 30 cal. gas check bullet was used with good results in a 7.62x39, with a finished size of .311". Since I was starting with a .308" bullet getting a thick jacket for this caliber was not a problem.

My goal is to develop a polymer jacketed bullet that is accurate at full power loads for the caliber, so I am toying with different ideas and plan on working with other calibers.

[Lloyd Smale]

Ill add this. Ive allways seen where shooting gas checked designs without the check effected accuracy. In my recent Beowulf testing this showed itself with coated bullets just like with conventional lubed bullets. It went from groups about doubling with hard alloys, to not even being able to keep the soft ones without checks on the target consistently. Ive done this same experiment many times in the past with many different bullets and calibers and I can only recall two times when if got decent results and ive NEVER seen accuracy improve. Sure didn't see coating changing any of that.

[popper]

To the original question, I get much better results in rifle when the base of the GC is NOT coated. Same with PB. I've also found 0.002-3" to be the best thickness of PC coating. Possible leading below that and no accuracy above that. Isocore alloy (same I use in pistol) pushed 145 gr PB to 2100 fps, 1:10 BO, no leading but coating allowed skidding. I have a 307 NOE nose sizer I might try using as a body sizer.
I can push PC way faster than any plated I've used.

[Dragonheart]

Since a bullet is steared from the rear there are several problems with shooting a gas check bullet without a gas check. First the base of a cast bullet has imperfections left from cutting the sprue; this varies between bullets and is an inherent problem with cast bullets. Powder coating seems to help this on plain base bullets by filling in the imperfections somewhat, and in theory should make a more stable bullet, but whether this provides any accuracy benefit in the real world I don't know.

A gas check leaves a smooth base and when properly set is perpendicular to the side of the bullet and is flat; A gas check bullet used without a gas check has the cut sprue problem as well as the base is not round because it is left unsized and this GC base is not really a bevel or a boattail. A bullet that is not round is an unstable bullet. Lab test have proven altering the base of a bullet as has a predictable effect on accuracy.

So far our testing agrees with Popper that the optimum coating thickness is .002-.003". Plated bullets lack the thickness and toughness necessary to handle spinoff at higher pressures because spinoff and chamber pressure are directly proportional.

It is my hope that we can utilize bullet design, body sizing, nose sizing and coating to create a more stable cast bullet that will be a satisfactory alternative to copper jacketed bullets. I will post any information I think will be of benefit and hope those that are interested in the same goal will do the same. Maybe several of us working together can make it happen.

[kbstenberg]

DH I am doing some catch up here. Some questions please.
Where did you get the straight wall mold for the 30 cal.? What lead alloy are you using? The rifle to test the bullets. What twist does it have? Are you putting the GC on an unPC base? What brand PC are you using?

[Phantom30]

Dragonheart. I am working with a BTHP mold design with no lube groves and no GC. I stand them up on a HP jig so the base gets a smooth PC. So you say if I size it down as far as I can go before PC'ing and then double coat and resize I can get high speed performance. I have been wanting to load these 240gr PC'd BTHPs in my 300 Win Mag. But was concerned about boolit integrity. 45br tried some time back with the 230gr lee mold and the boolits didn't make it to the 100 yard target.

[Dragonheart]

Dragonheart. I am working with a BTHP mold design with no lube groves and no GC. I stand them up on a HP jig so the base gets a smooth PC. So you say if I size it down as far as I can go before PC'ing and then double coat and resize I can get high speed performance. I have been wanting to load these 240gr PC'd BTHPs in my 300 Win Mag. But was concerned about boolit integrity. 45br tried some time back with the 230gr lee mold and the boolits didn't make it to the 100 yard target.

Starting with good quality molds that produce round bullets is a must if you want to go for accuracy. A boat tail bullet was designed for stability at longer ranges and may not be the best choice for coating due to possible uneven buildup at the base, but if you have it why not give it a try?

We have been nose sizing and sizing the bands. As far as cast bullets this is giving us about as round of a bullet as we can get with little to no run out. An out of round bullet is an unstable bullet and no amount of coating, lube, etc. is going to fix that.

As far as powder coating I have been trying several methods: Spraying nose down two coats, spray one coat tumble the second, tumble both coats. All the first coats partial cure and full cure on the second coat. Living on the Gulf Coast, humidity is a problem so I have good days and bad days. I don't know which process will work the best for you but a .002+ uniform coating is what you are looking for. I have tried sizing between coats and it does seem to work harden the polymer. But once again we just have not done enough testing to say what we are doing is the way it needs to be done.

We have been working with 7.62x39 and 30/06 with good results, with plans for 7X57 and 22-250 soon. A 300 Win Mag. is much higher chamber pressure and a big jump from what we have been doing. Our highest estimated chamber pressure is about 48K and so far so good, but we don't know at what point the polymer jacket will fail. Spinoff is directly proportional to chamber pressure and at that point a bullet will become unstable. The polymer is hard, tough and creates an excellent bond and we are surprised how well it has performed, but we just haven't tested enough. If you push the 300 Win Mag you may find out what we don't know. Good luck and please keep us in the loop as to your results.

[Phantom30]

Attached is my load plan for the 300 WIN MAG with the two Boolit molds I have been talking about. And yes the chamber pressures could be right up there. But the boolits are long and reduce the space available in the casing because of the COAL restrictions. Results in lighter loads less pressure. Thoughts?