30 caliber, 1 in 14" twist

[Spokerider]

I have a TC contender barrel that was re chambered to 30 40 Krag, by SSK. It is an early TC bull barrel and has the 6 groove, 1 in 14" twist.

I tried shooting some 210gr boolits from it [ because I was going on the Krag chamber when I chose these ] and they key-holed at 25m :confused: It was then that I investigated the twist of the barrel and discovered that the barrel was a 1 in 14" twist, and that TC made these during early production.

I also learned that the Bower .30 Alaskan caliber sported a 1 in 14" twist. Wondering what the benefit of a slow twist is / was, and why they chose it over a 1 in 10" twist?
Apparently, these early barrels were well made and are held in high reguard. My plan for shooting a heavy boolit are out....... how heavy a boolit can I go and get good accuracy to 200m? I'm thinking in and around the 150gr mark?

A friend can cast these for me......
http://noebulletmolds.com/NV/product_info.php?cPath=30&products_id=255
It does have a long nose for the Krag chamber.

Also, I slugged the bore at .3085-.309

Thanks for your thoughts.

[Ben]

The 311291 or the 311466 should work in your 1-14 twist.

You may also get some impressive velocities with your 1 - 14 twist and still have good accuracy.

Ben

[Larry Gibson]

With the 14" twist you can drive lighter weight cast to very high velocities with very good accuracy as Ben mentions. Look at the 311466 or the lighter 311465 Lyman Loverin designs or the 150 gr SP LBT bullets as very good bets.

Larry Gibson

[frnkeore]

I'm not sure why your 210 gr bullets tumbled, if your velocity is in the 1400+ fps range. I shoot 192 gr. 1.110 long plain base bullets (bore riding NEI design) and 190 gr PB, 1.160 long sharp spitzers, out of my 14" twist Douglas barrel at 1450 fps. But, I'm sure that the above type bullets will work in that speed range or the RCBS and Lee 180 gr bullet.

Is this a rifle or pistol barrel and what load are you using?

Frank

[Green Lizzard]

i would love for all my 30s to be 1 in 14

[Spokerider]

I'm not sure why your 210 gr bullets tumbled, if your velocity is in the 1400+ fps range. I shoot 192 gr. 1.110 long plain base bullets (bore riding NEI design) and 190 gr PB, 1.160 long sharp spitzers, out of my 14" twist Douglas barrel at 1450 fps. But, I'm sure that the above type bullets will work in that speed range or the RCBS and Lee 180 gr bullet.

Is this a rifle or pistol barrel and what load are you using?

Frank

I was attempting to work up a load with these boolits and Rx7. Started at 23gr [ approx. 1300 fps and keyholed ] and went to 28.5gr [ no more keyholes at approx. 1600fps ] working in .5gr increments.
All groups were poor, as in 3.5" at 25m, with the better groups being in an inch at 25m. This is a scoped 14" barrel, with a SSK muzzle tamer on it. This was the first time I have shot this barrel with any boolit or powder combo.

Yep, the scope and rings were tight....I checked.

I should be able to make one ragged hole shooting this scoped carbine off the bench at a mere 25m if the load shows any promise.

[Spokerider]

With the 14" twist you can drive lighter weight cast to very high velocities with very good accuracy as Ben mentions. Look at the 311466 or the lighter 311465 Lyman Loverin designs or the 150 gr SP LBT bullets as very good bets.

Larry Gibson

For the Loverin design, considering it's short nose and the long throat of the Krag, where would it be best to seat the boolit......with all of the grease grooves in the neck, or nose just off the lands?

Thanks.

[Char-Gar]

For many years I had a 1903 Sporter with a 1-14 Phiefer barrel in 30-06. It was a wonderful cast bullet rifles.

With jacketed bullets it would shoot 150s great, 165 grain bullet groups started to open up, but were still acceptable and with 180 grain bullets accuracy went south very quickly. I never tried anything heavier.

Cast bullets are denser than jacketed and therefore shorter for the weight. It is the length of the bullet and not weight that determines stability in a given twist barrel at a given velocity. At any rate, cast bullets up to 180 grains shot very, very well. I never went above that so I don't know where the upper limit is, but it would be heavier than 180 grains in that rifle.

For the most part, I used 311466 and 311467 in the rifle. I loaded the heavier of the two fast enough to take down 200 meter steel pigs even with a hit that was off center of mass. It was very effective and accurate. I used 4759 powder.

[felix]

Charles, the weight of metal on the circumference of the boolit is the tell-tale sign in your circumstance. Hollow points allow FASTER twists as does heavier metal on the circumference. Zinc boolits and flat nose boolits require umpteen twist. Hollow pointing a marginal flatnose, or too long of a pointed boolit, helps the existing design tremendously. ... felix

[Char-Gar]

Charles, the weight of metal on the circumference of the boolit is the tell-tale sign in your circumstance. Hollow points allow FASTER twists as does heavier metal on the circumference. Zinc boolits and flat nose boolits require umpteen twist. Hollow pointing a marginal flatnose, or too long of a pointed boolit, helps the existing design tremendously. ... felix

I got most of that, but the first sentence, no entiendo. To much tech speak, which I no hablo.

[frnkeore]

The loads that I'm going to post are for a rifle with a 26" barrel (as seen in my avatar), They are GCed bullets in the 1800 to 2100 fps range with no more that 30 fps ES in this rifle so, they'll be pretty stout for a pistol.

Lee 200gr
23 gr RX7
26 gr RX7

190 gr RCBS FN (180 RCBS fn mold)
31 gr AA2520
20 gr 4759

185 gr Lee
26 gr RX7
32 gr AA2520

175 gr SAECO
30 gr AA2520

Be sure your bullets are at least .310, your neck expander the same size (will give you a .0005 fit) and jam them as far as you can in the throat with your finger.

Frank

[Larry Gibson]

For the Loverin design, considering it's short nose and the long throat of the Krag, where would it be best to seat the boolit......with all of the grease grooves in the neck, or nose just off the lands?

Thanks.

If you want hunting loads and the rounds are pocket or bandolier carried (wrist, belt or on a shoulder holster strap) and the exposed portion of the bullet is exposed to the elements then I would seat the 311466 so the GC is at the base and leave the exposed grooves unlubed. That will probably put the front drive band close to the leade anyway. If loading out of a cartridge box the seat to the lands.

Size the 311466 to throat diameter and use an expander that gives .002 - .003 neck tension, probably the 31 M-die.

As with Frank I suggest RL7 or 3031 as the fastest burning powders to use. I prefer 4895 but all 3 should work. I'd also prefer a dacron filler as you'll be below 80% load density with any of them. Frank does not like the filler but that's not the discussion here. Up to you what you want. If that is a hunting handgun then the dacron filler will negate "powder positioning" and it will make the smaller charges ignite and burn more consistently. All of which most often means better accuracy.

Larry Gibson

[Char-Gar]

In the. Krag rifle any Loverin bullet won't be near the lands IF the round will feed through the magazine.

Only the bottom 2 or 3 grooves need to be lubricated in these bullets. Therefore the lubed grooves will be inside the case neck.

[nanuk]

I got most of that, but the first sentence, no entiendo. To much tech speak, which I no hablo.


what I read was: the important thing is the weight of metal at the circumference.

in other words, a zinc boolit, with a lead jacket should be better than a lead bullet with a zinc jacket.
Hollowpointing moves the weight to the outside, so you can drill a hole right through, and use a plug on the base to seal it, and it should work.

or else he said: Don't wash whites with colors...

I dunno...

[Spokerider]

In the. Krag rifle any Loverin bullet won't be near the lands IF the round will feed through the magazine.

Only the bottom 2 or 3 grooves need to be lubricated in these bullets. Therefore the lubed grooves will be inside the case neck.


That was my concern with the Loverin design......the fact that it would be no where near the lands if I seated full depth. If only two or three lube grooves are needed, then seating it out makes sense.
The gun is a contender single shot, so any OAL goes. I carry cartridges in my pocket when hunting, yep mixed in with pocket grit and grime.

What makes the Loverin an "accurate" boolit, more so than other designs? Is it the long bearing surface?

I like the idea of using Dacron. It worked well with the 45 70 loads I have worked up. When shooting the 299314 boolits in the Krag, I noted the wide ES within the 3 and 4 shot groups, up to 100 fps. I noted a trail of un burnt Rx7 left in the bore as well, following each shot.

Thanks for the info on the neck tension Larry....another bit of technical information that I don't have to guess about. It helps.

[frnkeore]

If you use .002 - .003 neck tension, be sure to pull a couple of bullets to see how much it resizes them. You don't want the base resized or distorted at all.

Frank

[Char-Gar]

I don't think the Loverin designs are more accurate than others. They are good, but others will do as well providing the fit is correct.

[runfiverun]

the loverign is just a tapered design and you get more boolit closer to more steel in some throat shapes.
two lube grooves is more than enough, most of my faster boolit designs only have one groove and no lube anywhere else.

[Larry Gibson]

The Loverin designs have more bearing surface and less nose. They fit long throated milsurp barrels much better and the lighter Loverins fir the longer necked cartridges in short throated commercial barrels better. They are known for better accuracy at higher velocity also. Many modern cartridges with short necks and short throats do not do well with Loverins because the GC generally has to be seated into the case below the neck. That can be detrimental to best accuracy.

Note to frank; I know you like to come back at me but .002 - .003 neck tension with a standard Hornady or Lyman GC will not deform the base and the bullets are not sized down. Pulled to many and measured them. The GC 'sizes the neck as the bullet is seated and the neck then gives minimal tension on the driving bands. Good thought though as it rings true with very, very soft cast bullets and softer PB'd cast. Appears the OP isn't casting softer bullets.

Larry Gibson

[Char-Gar]

With the longer Loverin bullets I size 1 to 3 top bands .301 to enable me to seat the bullet out so the gas check is in the case neck. These sized top bands give me a short bore riding nose.

[Larry Gibson]

With the longer Loverin bullets I size 1 to 3 top bands .301 to enable me to seat the bullet out so the gas check is in the case neck. These sized top bands give me a short bore riding nose.

I do the same with the 311466 for use in my 14" twist Palma .308W rifle. Pushing 2600+ fps with it and maintain 1 1/2 moa accuracy to 300 yards.

Larry Gibson

[Char-Gar]

I do the same with the 311466 for use in my 14" twist Palma .308W rifle. Pushing 2600+ fps with it and maintain 1 1/2 moa accuracy to 300 yards.

Larry Gibson

This is the reason I designed 311407 Mod with the top two bands .301 - .302.

[Spokerider]

I have asked my friend to cast these for me;

http://noebulletmolds.com/NV/product_info.php?cPath=31&products_id=80

COWW + 2% tin / 50% lead.

About powder choice, is there any advantage, accuracy or velocity to using something faster than Rx7 in the 14" contender barrel? 4227? 2400?
There is a trail of unburnt powder left in the bore with Rx7, and a huge muzzle flash, but that may just may be a product of short, muzzle tamer equiped type barrels.

[frnkeore]

4227 is a good powder in PB loads to 16 gr. GC's to 22 gr. I would also suggest that you try all your loads with and w/o the muzzle break.

Your alloy is a very soft one so, watch that neck tension. You don't need it with your pistol, at all.

Frank

[Larry Gibson]

A Dacron filler will help with the "trail of unburnt powder left in the bore with Rx7" and with 4227.

Larry Gibson

[Spokerider]

Thank you gentlemen, for your insight and sharing your knowledge. It all helps.

[Spokerider]

A Dacron filler will help with the "trail of unburnt powder left in the bore with Rx7" and with 4227.

Larry Gibson

Larry,
How much Dacron would be needed for these 152gr Loverin boolits and Rx7? I'll prolly start the load at 25grs of powder and go up from there.......to 29 or 30grs depending upon accuracy.

Thank you.

[Larry Gibson]

Larry,
How much Dacron would be needed for these 152gr Loverin boolits and Rx7? I'll prolly start the load at 25grs of powder and go up from there.......to 29 or 30grs depending upon accuracy.

Thank you.

What is needed is just enough Dacron to fill the space between powder and the base of the bullet. Start with chunks of about 3/4 gr (doesn't need to be exact) and don't wad it or roll it together to get it into the case mouth like a foam ear plug in your ear. Leave it fluffed, lay it over the case mouth and poke it into the case mouth until some of it is still in the case neck. I use a section of old Outers .22 cleaning rod to poke the Dacron into .30 thru .375 cals. That method lets the Dacron expand back out inside the case filling it. You can hold the chunk of 3/4 gr Dacron along side the case with your starting load and get a visual if it will fill the space. A little too much is ok but too little is not.

Larry Gibson

[Spokerider]

Thank you Larry. Will do.