The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools
Old November 9, 2012, 10:05 AM   #1
Rmitch223
Junior Member
 
Join Date: November 9, 2012
Location: Oklahoma City
Posts: 3
105 Amax load workup - Beginner needing advice.

Let me start by saying I am completely new to reloading.
My step dad recently bought me a Hornady LocknLoad kit to start reloading. Ive reloaded with him only a few times and I plan to study and learn as much as I can before I get started. I'm building my bench now and getting everything lined out to get started.

I'm currently thinking a lot about my initial load work up.
I'm going to be shooting 105gr Amax bullets threw a Rem 700 SPS Varmint in .243.

A friend on mine loaded up the following load for me that shot 1/2" groups at 100yrds.

105gr amax
42.5gr of IMR 4350
Federal 210M primers
Seated at 2.800 COAL

The COAL is longer than all my reloading books state. Is this too long? Feeds well and shoots well I just want to be safe.

I'm curious since this load shot so well that I should just duplicate it. But reloading manuals I have looked at recently say that this is too high of a charge weight and its exceeded max pressure by 6000lbs. (66,000lbs)

Is this a safe load to start with?

Should I start at 38gr and work up to it in .5gr increments?

The fired brass show a slightly cratered primer where the firing pin hits it, but the edges of the primer are not flattened. I will add pics of the fired brass soon. Is this a sign or too much pressure or is it just because the Rem 700 firing pin hole is larger than the firing pin?

Any advice would be greatly appreciated.
Please advise if any information needed to answer my questions is not provided above.

Thanks,

Ryan
Rmitch223 is offline  
Old November 9, 2012, 09:55 PM   #2
kilotanker22
Senior Member
 
Join Date: October 14, 2012
Posts: 411
I happen to have experience with that bullet in the same caliber and gun. 42 grains does seem pretty hot but if the primers are cratered a little but you have no other sign of pressure I think you are safe however I would suggest that unless you were there and watched him weight the charge I would work it up if I were you. The load that works well for me is. The 105 amax with 38.5 grains of h4350 can't remember the oal. My sps varmint will put that load in near one hole groups.
kilotanker22 is offline  
Old November 12, 2012, 05:01 PM   #3
Rmitch223
Junior Member
 
Join Date: November 9, 2012
Location: Oklahoma City
Posts: 3
can you check you OAL for me since your shooting the same bullet and gun?

I would really appreciate it

Thanks,

Ryan
Rmitch223 is offline  
Old November 12, 2012, 07:03 PM   #4
Brian Pfleuger
Staff
 
Join Date: June 25, 2008
Location: Central, Southern NY, USA
Posts: 18,612
Someone else's OAL means nothing to you and your gun. If it fits and functions in your gun, it fits and functions. Nothing else matters.

Newer Remington rifles have chamfered firing pin tunnels and will sometimes show primer cratering at normal pressures.

However, 2.800 is quite long for a 243Win cartridge. If that bullet is touching the rifling, you could be increasing pressures dramatically. QuickLoad internal ballistics software tells me that load is at least 62,000PSI and as high as 70,800psi if the bullet is in the rifling.

If you started at that load without working up to it, you did a very dangerous thing. You should always be starting at listed starting loads or 10% below max, whichever is indicated.

It's not always dangerous to exceed published max loads, in fact many of us load cartridges for which published data does not exist, but it is ALWAYS dangerous to start at high loads. One small mistake could be catastrophic. Maybe you set your OAL wrong (as I did recently) and are creating excess pressure by jamming the bullet in the rifling. Maybe you've got a small chamber or a fast lot of powder, too many variables to list.

Starting low lets you find these things before the pressures reach dangerous levels.

Your friend should also be aware of this fact and if he allowed you to shoot those rounds without working up to them I would never fire another cartridge that he created.
__________________
Still happily answering to the call-sign Peetza.
---
The problem, as you so eloquently put it, is choice.
-The Architect
-----
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.
Brian Pfleuger is offline  
Old November 14, 2012, 09:16 AM   #5
Rmitch223
Junior Member
 
Join Date: November 9, 2012
Location: Oklahoma City
Posts: 3
The COAL has been something I haven't completely wrapped my head around yet. I understand that it can be unsafe to seat them to far away from the lands and too close as well. That's why I put so much thought into making sure I do it correctly. The loads I previously shot loaded at 2.800" functioned and shot extremely well, but I don't know if they are jamming into the lands or not. Another thing that kinda confuses me is that SAAMI spec for COAL is 2.710" and I'm shooting very accurately loaded at 2.800". I'm just concerned this is too long I guess. I will know when I get some dial calipers I suppose, I'm just confused about it right now and probably making it more difficult than it really is.
Rmitch223 is offline  
Old November 14, 2012, 09:52 AM   #6
Brian Pfleuger
Staff
 
Join Date: June 25, 2008
Location: Central, Southern NY, USA
Posts: 18,612
There are three ways to get a good measurement on OAL in your gun.

The easiest and most accurate way is to get a Hornady OAL gauge and modified case. If you get one, post here and we'll explain how to use it correctly, as the instructions are somewhat lacking.

The second way, which kind of requires 3 hands, is to use a small rod, like from a cleaning kit, to very gently press a bullet into the chamber until in touches the rifling. Then, slide another flat ended rod (a wooden dowel of appropriate size works really well) down the muzzle until it touches the bullet and use a razor blade to mark the rod at the muzzle. Now, remove the bullet from the chamber and close the action. Slide the rod in the muzzle down until it stops on the breach-face. Mark it with the razor at the muzzle again. The distance between the two marks is the OAL that will touch the rifling with that bullet.

The third way is to use a fired case and size the neck ever so slightly until you can just seat a bullet by hand and it will stay in place. Leave the bullet out extra long, just barely in the case. Now close this round in your gun and extract it slowly and carefully, catch it so it doesn't go flying and change the measurement. Measure this round and repeat this procedure several times. I do it with a couple different bullets and cases to get a decent reading. I also rechamber the round several times to make sure that the length doesn't change slightly every time it's done because the bullet sticks in the rifling and pulls out of the case slightly.

Personally, I had some trouble getting good results with 2 and 3 until I figured out the techniques. It works pretty well now.
__________________
Still happily answering to the call-sign Peetza.
---
The problem, as you so eloquently put it, is choice.
-The Architect
-----
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.
Brian Pfleuger is offline  
Old November 14, 2012, 11:01 PM   #7
kilotanker22
Senior Member
 
Join Date: October 14, 2012
Posts: 411
I use the the last method that brian mentioned. I size the case neck and changer it well and force the bolt closed on the cartridge. I do this several times to get an accurate reading. Then seat the bullet an additional 50 thousandths or. .050. This has worked very well for me. Also all my cases are Winchester fire formed then neck sized.

Not that it will make a difference for you but my coal is 2.785 and that is. .050 off of the lands.
kilotanker22 is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 09:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.07753 seconds with 7 queries