powder burn rate vs. bullet weight

dongun · September 18, 2000, 12:29 PM

A friend recently bought a .257 Roberts in Rem. 700. He is having difficulty finding a sub MOA load. He is using IMR4350 with 100-120 gr bullets. Are these bullets too light for a slower burning powder like 4350? Does he need to change to a faster powder? Thanks.

P.S. I first posted this question in a thread in the rifle forum, then thought it might be better here.

Hutch · September 19, 2000, 08:49 AM

While M700's have a fine reputation for accuracy, the problem may not be with the load, but the rifle. Do the dollar bill trick to verify that the barrel is floated, etc. etc. As far as find just the right recipe, it may be the work of a few months to do. There are no guarantees that the rifel will EVER go sub-moa.

Southla1 · September 19, 2000, 03:45 PM

Hutch has a good point about it never going sub MOA, but I bet if you expirement enough it will (if the barel is truly free floated). If the only powder that he has tried is 4350 I recommend that he try several other powders listed in the manuals, start at the starting loads and work up, also try different bullets, different primers, different bullet seating dep[th etc. It may take some work but I bet it will turn out to be worth it.

------------------
Carlyle Hebert

Art Eatman · September 19, 2000, 06:08 PM

A trick which has *always* worked for me with a free-floating barrel is to make a shim of kitchen wax paper to insert at the front of the forearm. A 3/4" strip, folded until it is just thick enough that it takes roughly a five-pound pull to separate the barrel and stock enough to insert it is about right.

This acts as a damper, making the barrel vibrations uniform from shot to shot. Cheap, too. Try it and see what happens, before getting into a whole bunch of load testing.

I've used it successfully to improve at least 15 or 20 rifles...

Hope this helps, Art

DAL · September 20, 2000, 04:31 AM

Hey, Art, I hope this doesn't sound dumb, but have you ever tried that waxed paper trick on a barrel that's not free-floated? Would it have any chance at all of working?
DAL

------------------
Reading "Capitalism: The Unknown Ideal," by Ayn Rand, should be required of every politician and in every high school.

"Guard with jealous attention the public liberty. Suspect everyone who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are ruined."
--Patrick Henry, during Virginia's Convention to Ratify the Constitution (1788)

GOA, JPFO, PPFC, CSSA, LP, ARI, NRA

Southla1 · September 20, 2000, 06:43 PM

Art, I am sitting here chuckling. You use wax paper and I take a file card (I think they are called 3x5) cut a piece out of them and use it between the barrel and stock at the forearm tip. We must think alike!

------------------
Carlyle Hebert

WalterGAII · September 20, 2000, 07:45 PM

If the Rem. 700's not a varmint model, chances are that the barrel isn't free-floated. I recently bought a 700 VLS in .243. I free-floated the barrel myself, using the larger sanding disk with my Dremel tool. I can put five dollar-bills between the stock and the barrel. I also bedded the action at the tang and recoil lug with Marine Tex. Installed a Timney trigger, which is set at about 2#, and I'm shooting a hell of a lot better than 1 m.o.a.

I'd start by free-floating the barrel and adjusting the trigger down to around three pounds. Then I'd get really serious about working up loads. Yes, I would try a faster powder with the lighter bullets.

Kernel · September 21, 2000, 10:53 PM

To answer your question, IMO 4350 is not to slow for 100 - 120 gr bullets. My Powley Computer says 4350 has the optimal burn rate, if anything it's starting to look to fast with the 120gr bullets. Try Hodgdon 4350 or VV N150, they're in that same ballpark. It might be the rifle (or the bullet, the shooter, or the technique). -- Kernel

September 18, 2000, 12:29 PM	#1
dongun Member Join Date: May 7, 2000 Location: Central Arkansas Posts: 76	A friend recently bought a .257 Roberts in Rem. 700. He is having difficulty finding a sub MOA load. He is using IMR4350 with 100-120 gr bullets. Are these bullets too light for a slower burning powder like 4350? Does he need to change to a faster powder? Thanks. P.S. I first posted this question in a thread in the rifle forum, then thought it might be better here.

September 19, 2000, 08:49 AM	#2
Hutch Senior Member Join Date: February 12, 2000 Location: Birmingham, AL Posts: 1,124	While M700's have a fine reputation for accuracy, the problem may not be with the load, but the rifle. Do the dollar bill trick to verify that the barrel is floated, etc. etc. As far as find just the right recipe, it may be the work of a few months to do. There are no guarantees that the rifel will EVER go sub-moa.

September 19, 2000, 03:45 PM	#3
Southla1 Member In Memoriam Join Date: March 19, 2000 Location: Jeanerette, La. Near the Posts: 1,999	Hutch has a good point about it never going sub MOA, but I bet if you expirement enough it will (if the barel is truly free floated). If the only powder that he has tried is 4350 I recommend that he try several other powders listed in the manuals, start at the starting loads and work up, also try different bullets, different primers, different bullet seating dep[th etc. It may take some work but I bet it will turn out to be worth it. ------------------ Carlyle Hebert

September 19, 2000, 06:08 PM	#4
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	A trick which has always worked for me with a free-floating barrel is to make a shim of kitchen wax paper to insert at the front of the forearm. A 3/4" strip, folded until it is just thick enough that it takes roughly a five-pound pull to separate the barrel and stock enough to insert it is about right. This acts as a damper, making the barrel vibrations uniform from shot to shot. Cheap, too. Try it and see what happens, before getting into a whole bunch of load testing. I've used it successfully to improve at least 15 or 20 rifles... Hope this helps, Art

September 20, 2000, 04:31 AM	#5
DAL Senior Member Join Date: October 15, 1999 Location: Colorado Springs, CO, USA Posts: 653	Hey, Art, I hope this doesn't sound dumb, but have you ever tried that waxed paper trick on a barrel that's not free-floated? Would it have any chance at all of working? DAL ------------------ Reading "Capitalism: The Unknown Ideal," by Ayn Rand, should be required of every politician and in every high school. "Guard with jealous attention the public liberty. Suspect everyone who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are ruined." --Patrick Henry, during Virginia's Convention to Ratify the Constitution (1788) GOA, JPFO, PPFC, CSSA, LP, ARI, NRA

September 20, 2000, 06:43 PM	#6
Southla1 Member In Memoriam Join Date: March 19, 2000 Location: Jeanerette, La. Near the Posts: 1,999	Art, I am sitting here chuckling. You use wax paper and I take a file card (I think they are called 3x5) cut a piece out of them and use it between the barrel and stock at the forearm tip. We must think alike! ------------------ Carlyle Hebert

September 20, 2000, 07:45 PM	#7
WalterGAII Junior member Join Date: November 7, 1999 Posts: 1,516	If the Rem. 700's not a varmint model, chances are that the barrel isn't free-floated. I recently bought a 700 VLS in .243. I free-floated the barrel myself, using the larger sanding disk with my Dremel tool. I can put five dollar-bills between the stock and the barrel. I also bedded the action at the tang and recoil lug with Marine Tex. Installed a Timney trigger, which is set at about 2#, and I'm shooting a hell of a lot better than 1 m.o.a. I'd start by free-floating the barrel and adjusting the trigger down to around three pounds. Then I'd get really serious about working up loads. Yes, I would try a faster powder with the lighter bullets.

September 21, 2000, 10:53 PM	#8
Kernel Senior Member Join Date: November 21, 1999 Location: Madison, WI.... "78 Square Miles Surrounded by Reality" Posts: 923	To answer your question, IMO 4350 is not to slow for 100 - 120 gr bullets. My Powley Computer says 4350 has the optimal burn rate, if anything it's starting to look to fast with the 120gr bullets. Try Hodgdon 4350 or VV N150, they're in that same ballpark. It might be the rifle (or the bullet, the shooter, or the technique). -- Kernel