Monolithic Bullet Accuracy

[RockyMtnMT]

I think twist is vital to getting good performance from mono's. You have to remember that they by nature need more twist than lead core. It just has to a little different way of thinking about bullets. They start out a bit lighter for good stability, which gains a bit of mv. They retain more weight on impact so the lighter bullet will tend to act like a heavier bullet for terminal performance. It is a give and a take thing.

Now if you are building go fast for cal twist on your barrel and you have your cake and eat it too.

Steve

 

[HARPERC]

........There has never been any pork hit with a Hammer yet. I would lover to see some Hammered pork............They have killed wolf, moose, antelope, wtail, mulies, and elk. Oh and gophers........New tool is supposed to be in today so I can finish your order and get it in the FedEx box tomorrow morning....

May have got ahead of myself, pulled the 6mm out of the safe to adjust the trigger to something more usable, and the light strike you had when you shot it may not be an isolated event. Working on it.

No worries on the others, but I am excited to test them, and the rifle is at the front of the safe for the first time in a long time.

 

[RockyMtnMT]

........There has never been any pork hit with a Hammer yet. I would lover to see some Hammered pork............They have killed wolf, moose, antelope, wtail, mulies, and elk. Oh and gophers........New tool is supposed to be in today so I can finish your order and get it in the FedEx box tomorrow morning....

May have got ahead of myself, pulled the 6mm out of the safe to adjust the trigger to something more usable, and the light strike you had when you shot it may not be an isolated event. Working on it.

No worries on the others, but I am excited to test them, and the rifle is at the front of the safe for the first time in a long time.

Uh oh. Pull the bolt apart and make sure it not gummed up.

Steve

 

[royinidaho]

Did some study on a Kiwi DCM thrread and adjusted my approach on Hammer Hunter 393 grain prototypes.

I'm running a 10 twist 30" PacNor.

A max load of 50 BMW gave 1/2 MOA at 300, 547, 849 and 1126 yards.

Switched to Reloder 50, a bit slower.

Went up to 146 grains and got 3125 FPS. Upped the charge to 146.6 and got 3126 FPS MV with the MagnetoSpeed V3. Onlty 1 FPS difference???

This is where I learned something about HBN coating processes. Story for another tiime.

With a different batch of HBN coated Hammer Hunters 146.3 grain of RL-50 gave 3109 FPS loafing along pressure wise.

Upped charge weight to 147 grains resulting in 3110 FPS. Me things a couple more inches of barrel is needed for this very slow powder.

The exciting thing about these two shots is that they grouped CTC at precisely 0.25 MOA @ 300 yards.

A bc input of 0.46 G7 is getting me close at 1126. This additional velocity reduces 1126 yard drop right at 1 MOA according to AB. Tomorrow will tell the tale. I'm confident I'll get good numbers for that distance and will then head out to 1661 yards.

I'm shooting only 2 shot groups as I'm running low on projectiles. Hint

 

[RockyMtnMT]

I hear ya Roy. Sounds like you got it dialed in. How many ya need?

See I was thinking the other day that you need to run faster not slower powder. Doesn't Kirby like Retumbo in that rifle? I was wondering about RL33?

Steve

 

[snox801]

I was also thinking h-1000 or rl33 for that load. I'm watching you closely Roy as I'm planning on using hammers In my .375 AM. I will have a 34" tube cause why not I'm not gonna be carrying that thing far that's for sure.

 

[royinidaho]

I hear ya Roy. Sounds like you got it dialed in. How many ya need?

See I was thinking the other day that you need to run faster not slower powder. Doesn't Kirby like Retumbo in that rifle? I was wondering about RL33?

Steve

Steve,

Kirby's load for the 375 AM is 142.5 gr of Retumbo behind the 350 SMK for 3250 MV.

That powder charge gave me extreme pressure every so often. Maybe 2 or 2 out of 10 shots. Kirby indicated it was he 375 AM head stamped Jamison brass neck thickness variations. For the life of me and my not so great Franklin Armory digital calipers I couldn't measure any significant neck thickness variations.

Do a search on Broz's experienc with Retumbo in his LRKM. IIRC he experience excessive pressure something like every 6th or 7th shot.

KiwiGreg says that RL-50 is slower than 50 BMG and is what he uses with 435 grain pills.

My recent shots show RL 50 to be about as slow as the 30" barrel will stand.

I'm thinking a smaller contour 34 inch barrel will produce something in the range of 3300 with the 393 HHs. Kinda makes me want to shoot this sucker out....

Anything over 146 grains gives ziltch velocity increase but the muzzle blast moves a lot of gravel. My biggest bother is that the predominant wind is in my face at my range.

Rained all day today thus no shooting. Tomorrow will be a better day I hope. If those last two shots a 300 are an accurate indication of what happens at 1126 I'll then see if I can hit my bullet catcher. I'm excited that I may wll be able to center a 12" target at as far as the big girl will reach.

As to how many? 4 shots at 1126, 1661 and 1760 and I have 7 left. Mayby 1000 will do...

One thing I'll say for sure, I'm flat done with repointing SMKs.

 

[RockyMtnMT]

Steve,

Kirby's load for the 375 AM is 142.5 gr of Retumbo behind the 350 SMK for 3250 MV.

That powder charge gave me extreme pressure every so often. Maybe 2 or 2 out of 10 shots. Kirby indicated it was he 375 AM head stamped Jamison brass neck thickness variations. For the life of me and my not so great Franklin Armory digital calipers I couldn't measure any significant neck thickness variations.

Do a search on Broz's experienc with Retumbo in his LRKM. IIRC he experience excessive pressure something like every 6th or 7th shot.

KiwiGreg says that RL-50 is slower than 50 BMG and is what he uses with 435 grain pills.

My recent shots show RL 50 to be about as slow as the 30" barrel will stand.

I'm thinking a smaller contour 34 inch barrel will produce something in the range of 3300 with the 393 HHs. Kinda makes me want to shoot this sucker out....

Anything over 146 grains gives ziltch velocity increase but the muzzle blast moves a lot of gravel. My biggest bother is that the predominant wind is in my face at my range.

Rained all day today thus no shooting. Tomorrow will be a better day I hope. If those last two shots a 300 are an accurate indication of what happens at 1126 I'll then see if I can hit my bullet catcher. I'm excited that I may wll be able to center a 12" target at as far as the big girl will reach.

As to how many? 4 shots at 1126, 1661 and 1760 and I have 7 left. Mayby 1000 will do...

One thing I'll say for sure, I'm flat done with repointing SMKs.

3300fps is where, in my mind that girl should be. It may just be more barrel needed to get there. The only place that I have really like retumbo is in 300 rum. I still wonder about the rl33 in your shorter barrel? Might be worth a note to Kirby and see what he thinks.

I'll try and get some more cut for you today. I want to see you catch one at 1760.

Steve

 

[284ackley]

My goal is to build something that will accurately shoot the mono's. I have not had much success getting great accuracy with any of them in my current rifles. I usually hear things like "some barrels like them and some don't" I would like to hear from people who shoot them with great accuracy to attempt to find similarities in barrels, cartridges, or maybe there is one particular bullet that seems to shoot good in anything.

Also, this setup should be capable on elk sized game out to 700 yards.

Thanks,

I shoot only Barnes in all my hunting setups. TSX, and TTSX seem to prefer different guns but both shoot 0.250"moa all day in my customs. Calibers include 25-06 and Ack; 280Rem and Ack; 270WSM; 300 WinMag; 300 and 330 Dakota; 300 H&H. .375H&H Ack shoots 3/8"-1/2" moa with 270gr TSX bullets. Have shot Moose, huge Zebra and other Plains game, Antelope, deer and hogs. All were near immediate kills. Now working up LRX loads. You do have to move off the lands. I start at 0.050" off and in general usually end up at 0.0250" to 0.030" off the lands.

 

[DoneNOut]

I'm glad I check dates now. 2016 thread.

 

[284ackley]

I'm glad I check dates now. 2016 thread.

LoL

 

[Rich Coyle]

How 'bout this for a barrel that didn't and a barrel that did, but they were the same barrel?

I had a rifle built with a Siskiyou barrel. I had him make the barrel with a slim 22" profile but add 4" to it. It was a guaranteed 2MOA rifle. The cartridge was a short fat before short fat was in. It would hold on in the chamber and another in the magazine.

After a couple hunting seasons I had an adjustable brake installed. The 'smith who installed it told me, "If it doesn't put two close together it's not gonna put three close together." I dialed it in with only fifty shots. I took the 'smith to the range and fired two shots on the target and brought it to him. They were 1/2" apart. He said, "There're only to holes." "It only holds two," I told him. You gotta shot three." I put up another target and fired three. The group measured 1".

I later discovered Barnes are suppose to be started about .050" from the lands. I was loading mine against the them. The last rifle in which I used Barnes the preferred location was .120" from the rifling. This is almost 1/8".

I was firing original 7mm 150 grainers at 3,200 feet per second.

It sure appears I need to check what I post. These groups were fired at 300 yards.