30-30 tight barrel - Glass half full?

[RedDust]

I posted a while ago about unexpected high velocities from my re-barreled Marlin 336.
http://castboolits.gunloads.com/showthread.php?331211-Unexpected-high-velocities-from-slow-twist-rebarrel

It's a dedicated cast-only rifle used for target competition and hunting - It had about 2000 rounds through it last year.
The original 20inch, 1 in 10" twist microgroove in 30-30 was replaced with a 26", 1 in 14" twist hand-lapped chrome-moly barrel in 30-30, with a Marlin 30-30 profile.

The aim of the long barrel was to increase heft and sight radius for target shooting, and the slow-twist was to give higher velocities for Cast bullet hunting.
Well I'm happy with the lower velocity, lighter projectile target loads.
And I'm happy with the heavy projectile, lower-velocity target loads.
But the heavy projectile (184gr checked and lubed) hunting loads lose accuracy at velocities around 2000fps - That's 300fps better than the 10" twist barrel, but I was hoping for a bit more.

Am I just a whinger?
Is the glass really half full?
I mean 184gr hunting projectiles at 1970fps aren't going to bounce off, but I wanted to flatten the trajectory a bit.
Should I be happy with what I've got or do you have suggestions for the hunting loads?

Background:
I was quite happy with loads using the CBE 313-112gr GC projectile sized to .311 for target shooting (124gr gas-checked and lubed) and was waiting on arrival of NOE's 311041 copy for hunting and for target use at 100m in windy conditions.
Well the mold arrived and I had a few problems - The SAAMI spec reamer is just right for a .311 on the drive-bands projectile, but I couldn't seat to the crimp groove. Did a "pound-cast" which confirmed chamber dimensions, but couldn't accurately measure bore and groove because it's a 5 groove barrel. I faffed around nose-sizing projectiles and found that it's a "tight-barrel" .298 in the bore. Well nose-sizing projectiles 2 thou was a real pain, even in 1 thou increments, so a leade-reamer was made and used to just allow seating of the projectile - barely engraves a .300 nose.

I did some load testing today - I'm happy with the target-load potential, but I'm not getting the velocities I wanted for hunting. I think it's a combination of high pressure and projectile extruding as the bands are swaged from .311 to .3075, and the nose is engraved.
All Projectiles cast from 50:50 range lead (cast Pistol Projectiles):COWW, plus 1/2 bar plumbers solder and one oz magnum shot per 10lbs lead. Water dropped.
Target loads:
CBE 313-112gr: 50m low recoil load. 9gr TrailBoss. 1430fps. 5 * 10 shot groups at 50m averaged 1.52". Best 7/10 shots average over groups =1.1" (I just churn these out and don't weigh them, and expect a few "fliers", hence the additional 7/10 group). Still shoots better than I can hold offhand at 50m with irons).

CBE 313-112gr: 100m low recoil load. 19gr H4198 (ADI2207). 1900fps. 5 * 5shot groups at 100m averaged 1.8"

I tested the NOE 311041 copy today with H4895 (ADI2206H) at 24gr, 26gr and 27gr H4895 charge-weights just to get an idea of accuracy/pressures before I move to 100m and use finer charge intervals.
NOE 311041 copy: 100m windy weather target load. 24 gr H4895. 1830fps. 5 * 10 shot groups at 50m averaged 1.38". Best 7/10 shots average over groups =0.81". (from experience, a load around here should be OK at 100m, i.e. not doubled in size, as rifle was getting a bit warm on a 10 shot load-testing string.)

NOE 311041 copy: work-up for hunting load. 26 gr H4895. 1970fps. 5 * 10 shot groups at 50m averaged 1.86". Best 7/10 shots average over groups =1.07".

NOE 311041 copy: work-up for hunting load. 27 gr H4895. 2030fps. 2 * 10 shot groups at 50m averaged 3.04". Best 7/10 shots average over groups =1.7".
No leading, but accuracy is gone, so I stopped after 2 groups.
Pressure must be up a bit for the 27gr load as I can feel very slight resistance when chambering a once fired case, unlike the 26gr load which is still at "only neck-size required" pressures.

[starnbar]

a hot barrel and heavier load if only by one grain of powder can make a real difference. Try backing down on the load with your 4895 and try another powder too sometimes that can make a difference I have a marlin that shoots great with 2400 and my winchester cant group with the same load.

[guicksylver]

Well...good morning...
Interesting thread....
I think your reasoning MAY have been counter intuitive...I say this because in SOME ways cast boolits act the same as jacketed...

Your 1-14" twist will be great for higher velocities with LIGHTER boolits..however it will be marginal with heavier boolits unless you can push them faster...and that my friend is where you run into problems with cast...there have been battles waged on this site on how to get cast boolits to perform at velocities over say 1800 fps....

Staying around 1600 FPS is a safe zone for the casual caster /shooter above that you are dealing with an entirely different set of dynamics...that is if you are expecting 1900 fps and bench rest accuracy..

On top of all that trying to do it with the platform you are using poses a real challenge..


Oh and BTW ..the 311041 at around 1600FPS out of a 1-12 ( standard 30-30 twist) has taken many a deer...

[Larry Gibson]

RedDust

A 170 gr 311041 style of cast bullet will be just fine out of your 14" twist. It will stabilize at around 500 - 600 fps and shoots well into the 2500 - 2600+ fps range out of 14" twist .308Ws and 30 XCBs. Your 311041 out of your 26" barreled 14" twist 30-30 should push 2250 - 2300+ fps with accuracy. To do that you need to do the following;

cast an excellent bullet of appropriate alloy
size correctly
Use a correct lube
use a quality crimp on GC properly seated
use a correct powder

I'm going to probably, at least to some, be a little blunt here. No disrespect, embarrassment or put down intended. I'm just trying to help.

Let's discuss the bullet first; the NOE 311041 is an excellent rendition of Lyman's and should cast excellent bullets.....no problem there. However, the alloy you are using is probably just fine for velocities up through 2000 fps as you've found.

"All Projectiles cast from 50:50 range lead (cast Pistol Projectiles):COWW, plus 1/2 bar plumbers solder and one oz magnum shot per 10lbs lead. Water dropped."

With the range lead and COWWs you probably have 1.5% or antimony....maybe and little to no tin. Adding the 1/2 bar plumbers solder tells us you added some tin but how much? What is 1/2 bar of what size bar? What was the lead to tin proportion? If it was a 1 lb bar of 50/50 solder you added 4 oz of tin by adding the 1/2 bar. Why the "one oz of magnum shot"? It contains 3 -5% antimony so you added 3-5% of one oz? So okay you ended up with basically a 96/1.5/2.5 alloy.......good for 1900 +/- fps but not good for much higher with a 311041 design bullet. The antimony to tin ratio is not even that good for heat treating or WQing to harden the bullets.

I suggest you initially use an excellent alloy so you will know the real HV capability of your rifle. You can then try other alloys thus having a yardstick to measure their performance by. I suggest you either make up some real #2 alloy (90/5/5) or you buy some. You will be amazed at the quality of the cast bullets from #2 alloy and how well they will shoot in your rifle. If you can't do that then mix up and alloy 10 lbs of COWWs + 2% tin (94.5/3/2.5). When casting cut the sprue off immediately after hardening and drop the bullets into water as soon as possible.

You should then weight sort the bullets and use the top heaviest half for best results on target. The others can be used for sighters/foulers or remelted and cast again.

Now let's discuss seating the GC, sizing the bullet and lubing the bullet. A quality Crimp on GC should be used. I use Hornady's exclusively because I have tested all the others at HV (above 2200 fps) and the Hornady's give the best results. The GC must seat firmly and flatly on the GC shank of the bullet. If there is excessive sprue still on the base of the bullet it can be cut off with a sharp knife with the bullet held on a block of lead. You might want to cut those off when weight sorting before weighing for better consistency. A GC seater should be used to seat the GC and crimp them in a separate operation from sizing, either with a lubrasizer of a push through sizer. I use the Lyman GC seater with my Lyman 450 to seat/crimp the GCs with an appropriate size H&I die.

Next the bullet should be lubed before sizing. After the bullets are GC'd I then lube them in the Lyman 450 with an H&I die of the "as cast diameter" of the bullets. An appropriate lube for HV is essential. While many will work by eliminating leading many not as accurate as others. I have tested many lubes at HV and have found 3 currently available lubes that give the best accuracy; White Labels 2500+, 2700+ and NRA 50/50 lubes. All my HV bullets (2200 - 3000+ fps) are lubed with 2500+ or Javelina (no longer available). I use mostly 2500+ simply because it always gives the best accuracy of any currently available lube I have tested.

Once the bullets are GC'd and lubed they are then sized to a correct diameter in a push through sizer. You are using a .311 sized bullet that is swaged down into a .3075 groove diameter barrel. Many expect the lubed cast bullet to be swaged down just to groove diameter.....however that is not the reality. There is a layer of lube and fouling the bullet must also ride on. That's another reason a softer quality lube is so important. Tests recovering .310 - .311 sized cast bullets fired in .308 groove diameter barrels shows us the bullets are swaged down and additional .003 - .005" under groove diameter. What that means is as your .311 bullet is getting kicked very hard in the rear it is sized/swaged down .006 - .008"......that is a lot of swaging down under extreme pressure in a short period of time (milliseconds). Can we agree there is probably a lot of damage/unbalancing of the bullet occurring? What I'm getting at is you might want to try sizing the bullets after GCing and lubing at .310 or .309 instead of .311. better to do some of that swaging under less pressure and more controlled conditions before shooting the bullets.

Now then, let's discuss the powder used. H4895 is a very fine powder to use in a 30-30 under a 170 gr cast bullet IF you will be satisfied with 1800 - 1900+ fps........If you aren't satisfied with the (the gist of your thread) then consider changing powder to a slower burning powder. The problem you are faced with is one of case capacity. You just aren't going to get enough of a truly slow burning powder such as RL19, H4831SC or RL22 into a 30-30 case to achieve any meaningful increase in velocity. There is one powder that does fit the bill though; LeveRevolution powder. With it you can push 2400 fps with the 311041 while not exceeding the SAAMI MAP for the 30-30. It also has a slower time/pressure curve rising to peak psi which means the bullet is getting a gentler push down the barrel.

I have a 24" M94 30-30 and push 2300 fps (just under the RPM Threshold for the 12" twist) using LeveRevolution under my Lyman 311041 while maintain 2 1/2 moa (10 shots with aperture sights). There is no reason your rifle shouldn't do as well if not better.

Larry Gibson

[Char-Gar]

I once had a Springfied 03 fitted with a 1-14 30-06 barrel that I used for shooting cast bullet silhouette matches. I used Lyman 311467 at well over 2,000 fps and it would take down the 200 meter rams with great authority even with a fringe hit.

It is not the weight of the bullet that determines how fast it can be pushed with a given twist. Cast lead alloy bullets being heavier for their length than jacketed bullets will also be shorter than a jacketed bullet of the same weight. A 1-14 twist barrel will push a 200 grain gas check bullet well over the speed your bullet rolled snake eyes.

When you send cast alloy bullets down a rifled barrel at or in excess of 2,000 fps, the small things that were not important at lower speeds, become very important. I am talking bullet temper, size, bullet design, quality of casting, powder choice and charge weight.

Bottom line is I feel confident that the twist of your barrel is not the source of your inability to push a given bullet above 2,000 fps with accuracy.

[GhostHawk]

3/4 full and reread what Larry said.

[RedDust]

Thanks all for the useful comments and suggestions - especially Larry, whose posts are always worth reading.

Looks like I can work on this progressively. I'm in a rural area so some supplies will take time.

I will mix up a batch of COWW and Tin as per Larry's suggestion for 94.5/3/2.5 for the higher velocity loads.
I'll be travelling to the City in the next month or so and will run ingots of COWW, recycled cast pistol projectiles, and my current mix over the XRF at a mate's workplace to see what I really have.
My current mix seems to harden well when water-dropped. I normally cast in the morning and size(lubed)/check in the afternoon - If I leave until the next day then experience shows that the projectiles harden enough to be really stiff through a Lee push-through sizer on an O-frame press, with each bands engagement detectable through the press handle. The amount of 60/40 Sn/Pb solder I add is empirically based. A quarter of a bar added and temperature and timing are still fiddly when casting, Half a bar adds enough for perfectly cast projectiles every time.

I've been slack on sorting heavies by weight, mainly because weighing on my beam-scale is a pain. I've ordered an electronic scale and will pull my finger out and use the beam scale until it arrives. It might reduce the fliers in the target loads and may reduce the group-size growth with velocity by reducing the frequency of hidden unbalancing inclusions. (As Larry has posted before and reminded me here).

I'm good with the bases - they're rejected if there's sprue-stick-up, divots, or a gas check won't fit square. A lot less rejects now than when I started casting.

Some food for thought re crimping gas checks and lubing has been provided. I currently very lightly lube with White Label 45-45-10 tumble lube, size and gas-check in a Lee push-through and then very lightly tumble lube again. I use Gator gas-checks (Hornady's are not as available locally) and they seem to crimp well - They stay on the projectile if I pull a projectile using a collet type bullet-puller.
I will try sizing to .310 and .309 to allow for the tight barrel, rather than sizing just for the chamber - Hopefully this will smooth out the pressure/time curve a bit at higher velocity.

LeveRevolution powder will have to wait as it's not available locally, and I'll have to see how far I can go with the current lube set-up before investing in a lubrisizer, unless there's a high velocity lube I can finger-apply.

once again, thanks for the comments - I'll post some updates as I make changes, just in case others are interested.

[RedDust]

Thanks for the assessment GhostHawk - Realistically I probably am closer to 75% there.

These are examples of what I'm getting with the NOE 311041 copy.
197298
Looks like scattering is happening as pressure/velocity increases (erratically?), hence the vertical spread.

I've started on the incremental improvements, following Larry's advice.
I can work on: casting an excellent bullet; using a quality crimp on GC properly seated; and, sizing correctly.
Using a "known quantity" (more appropriate) alloy; using a better lube; and using a better powder will have to wait a bit until they can be sourced.

The aim within these constraints is to see if I can do enough to get the 24gr/1830 accuracy at a 26gr/1970fps level. I don't think anything higher is doable with this powder, current alloy and lube.

I weight-sorted/checked my casting consistency first.
121 projectiles weighed as follows:
Wt(gr) Freq
178.4 2
178.5 2
178.6 13
178.7 12
178.8 31
178.9 46
179 14
179.1 1
I'm fairly happy with my casting consistency - .6 gr range from lowest to highest on an approximately 178.9gr projectile. (all water dropped)
As per Larry's suggestion on bases/GC seating I sat each projectile on a surface plate and any discernible wobble due to sprue dimple (almost imperceptible) was corrected with a chisel bladed craft knife before weighing. (so little material was removed that it wasn't detectable in before/after weights).
I also discarded everything below 178.9 gr, and the one odd projectile over 179gr, giving me 60 projectiles of 178.9 or 179gr (about 50% of the light ones discarded.)
Gas checks were fitted square and then crimped using a lee .311 push through sizer that just kisses the drive bands.
I then sized to .310 using an NOE body sizer. (I haven't got a .309 bushing yet, which is a pity as I suspect that sizing will be the critical element in reducing the vertical spread at higher pressures/velocities).

Projectiles are now left to harden up before testing next week. 60 is not many, but hopefully enough to see if there are any obvious differences in 3 * 10 shot group sequences at 24 and 26gr H4895 charges.

[RedDust]

These are examples of what I'm getting with the CBE 32-20 projectile in the 30-30.

197299

Although these are "fit for purpose", I thought that I may as well play with these too while casting/weighing for the heavier projectiles, just for the heck of it.

I'm not quite as happy with my casting consistency with these.
Wt(gr) Freq
119.7 1
119.8 0
119.9 0
120 0
120.1 0
120.2 0
120.3 2
120.4 11
120.5 19
120.6 27
120.7 66
120.8 31
120.9 1
121 5

1.4gr range for an approx. 120.7 gr projectile. - could explain the 3 fliers per group, especially the super-light or extra heavy outliers.
Not sure of the reason for the greater range in weights than the heavier projectiles - I suspect it's due to the lighter weight and TL/loverin type lube grooves - perhaps more surface area:lead ratio exacerbating tiny differences in casting technique/temperature-control/fill.

I meant to sort these to only include the 120.7 and 120.8gr projectiles, but messed up and accidentally added the 120.6grainers to the keeps instead of the culls.

I checked the bases on the surface plate - better sprue-cutting on these than the 311041s with no clean-up required.
Instead of just pushing them through the .311 lee to crimp gas checks, I followed Larry's suggestion and crimped gas checks using an NOE body sizer at .313, which barely kisses the drive bands.
The projectiles were then sized to .311 through the Lee. They do look "nicer" when subjected to the 2 stage crimp then size process rather than the single stage size and crimp to .311 process.

Half of the projectiles were then further sized to .310 through an NOE body sizer. I'm not sure if this will benefit the low velocity loads as I don't think that pressures are an issue, and without a big nose the thing that centres these projectiles in the chamber is the neck and drive band fit. Also not sure how well the TL/loverin type grooves will work when sized so much.

waiting to harden up (water dropped) before testing next week.

[barrabruce]

309 302 loose chambered 1:12 30-30 4 groove of once apon a time sharp rifling
Iv'e developed in my 30-30 loose spec'd bore and loads with.
4.2 gns bulleye 150-170 pb mouse fart loads that shoot real well
5-6 gns ap50n as above .
2205 15.8 grns 150-170's pp'd
2207 21-24 gnrs 150 pp
2206 27 grn 150 pp
2206h 29 gn 150 -170 pp up to 34 gns
2208 32 gns 150-170s pp
even 2209. not much luck...good accuracy but fertilized grass in front of the bench at the range.
bm2 etc a few test loads worked well.

2206h is my go to powder for paper patching fast loads for my rifle.
I have little left or 2207 and 2206h from 2kg tins I used up.
Using up some some Mullex 2206 and 2205 tins.(20 + year stuff)
I get mummies with 2208 as I think I can't get the pressure to really burn the stuff.

I rarely use gas checks....but I was getting an 1 1/2 5-10 shot groups at 100 yrds using lee 170 fp ww + strip or 2 printers lino in a 5kg pot. It casts like water.
Hornady gas checks.
Speed green lube and 28 gns 2206h in My gun.

I load long and like the nose to engrave the rifling and the band hard up against what ever it touches in there.

If you put 50 pp'ed bullets through it un lubed....it will polish that bore up to a mirror.

[KirkD]

Thank you, Larry Gibson, for taking the time to write that very instructive post. There are a lot of good posts on this forum, but I copied and saved that one.