105 Amax load workup - Beginner needing advice.

[Rmitch223]

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

 

[Okie4570]

If it's showing pressure signs, back off and work up, as you stated. You're almost 2gr too hot according to IMR. Not saying that I don't have some loads that are over the max though. I've had many flattened primers. COAL will vary by rifle, don't let your book tell you what it should be, find the right length for your rifle.

 

[MoBoost]

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

Holy hot load batman! That's way too hot even for 243AI. I mean, if it works in your gun - great, but I wouldn't post that load data ...
Accuracy load is 37.0-38.0 IMR4350 with 105AMax (mine is 37.5 with 105 Moly).

http://www.6mmbr.com/243Win.html

There is a lot more happening with pressures - primer is only one of the signs, and usually the last one:
http://www.massreloading.com/reading_pressure_signs.html

 

[ASP785]

I typically get case head expansion before I get primer signs. This is usually coupled with an ejector marking on the head. I would look for these signs first. I would suspect that your brass life would be very short 2-3 reloadings with that load before the primer fit is too loose.

I never recommend beginners trying to turn their cartridges into something they are not. Stick with published load data until you become experienced at reloading and recognizing the various signs of over pressure. There is really no reason to squeeze the last few FPS out of a cartridge at the expense of safety.

 

[Pulp]

Somebody correct me on this if I'm wrong, but I'm thinking that published COAL is the minimum. Do not seat shorter than the COAL, as deeper seated bullets equals higher pressure. Longer than COAL is OK, as long as it functions in your rifle.

 

[ssgrock3]

first thing you need is a reloading manual. Speer makes a great one and there are many of them out there, but speer and a couple others are the bible to reloading. Don't color outside the lines as a new reloader.

 

[victor3ranger]

Check out how much your fired brass has stretched, might also give you a good indication of over working your brass with a super hot load that isn't showing much over pressure signs.

 

[dlbleak]

typically, i will see better accuracy with reduced loads. every rifle is different though. its a PITA but you can tap and thread the primer pocket of a case and "push" the bullet to the lands with a long bolt or piece of all-thread. once you get the the rifling, back off about a quarter turn and measure. you will only have to make one of these jigs for each of your rifles. not a bad way to spend an afternoon and usually worth the results.

 

[Rmitch223]

Holy hot load batman! That's way too hot even for 243AI. I mean, if it works in your gun - great, but I wouldn't post that load data ...
Accuracy load is 37.0-38.0 IMR4350 with 105AMax (mine is 37.5 with 105 Moly).

http://www.6mmbr.com/243Win.html

There is a lot more happening with pressures - primer is only one of the signs, and usually the last one:
http://www.massreloading.com/reading_pressure_signs.html

I'm going to work my load up, after realizing what pressures this load was capable of I feel that I shouldn't even have shot it. A friend loaded it for me and I wasn't aware of the load data at that time. It shot great and I don't believe there were any pressure issues. My Lyman manual says the min load is 35.2 and the max/accuracy load is 39.2. (IMR-4350 & 105amax)
What load should I start with? the min and work up in .5 increments? I was thinking of loading 5 different charge weights with 10 of each.

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. I plan to use the technique Ive seen mentioned before to measure the COAL as soon as I pick up some dial calipers. 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.

Update:
I checked my OAL using using a case that would hold the bullet tightly and was still moveable by hand. barely hand seated the bullet into the case. Then I chambered it many times and closed the bolt and measured each time. 90% of the time the measurement was 2.822", some measurements came out to around 8.245" but I believe the lands may have been slightly pulling the bullet out to that measurement when I was ejecting. So with 2.822" I should be right where I need to be with a OAL of 2.800" right?

 

[Okie4570]

Mark your bullet with a black dry erase marker, or suet from a match on an unprimed dummy round. You'll be able to see if the lands are touching the bullet or not. You'll have to be carefull not to rub it off when loading or unloading.