44 mag reloading technical question

[gregintenn]

I have an 1894 Marlin. I believe it has a 16" barrel. I have the sights regulated for factory Magtech 240 grain ammunition. It is very accurate in this rifle by the way. I loaded some Hornady 240 grain xtp bullets over 21 grains of alliant 2400, and they print groups 6-8" higher than the Magtech ammo.

 

I wasn't expecting this much variance with the same weight bullet. The handload should be faster than the factory, and the xtp has a higher ballistic coefficient than the Magtech, so I would expect it to be a bit higher, but this is a lot. 

 

This handload isn't nearly as accurate as the factory loads either.

 

Is there any way to predict what load may print to the same point of impact as the factory ammo, or is it jus trial and error?

 

 

[R_Bert]

I have an 1894 Marlin. I believe it has a 16" barrel. I have the sights regulated for factory Magtech 240 grain ammunition. It is very accurate in this rifle by the way. I loaded some Hornady 240 grain xtp bullets over 21 grains of alliant 2400, and they print groups 6-8" higher than the Magtech ammo.

 

I wasn't expecting this much variance with the same weight bullet. The handload should be faster than the factory, and the xtp has a higher ballistic coefficient than the Magtech, so I would expect it to be a bit higher, but this is a lot. 

 

This handload isn't nearly as accurate as the factory loads either.

 

Is there any way to predict what load may print to the same point of impact as the factory ammo, or is it jus trial and error?

 

If you have a chronograph, measure the velocity of factory load, and your hand load.  Reduce the charge of the handload by the ratio of velocities.  That will give you a place to start.  Be watchful of squib rounds as you do this. 

 

BTW.. if you don't have a chrony...get one. 

Edited November 21, 2013 by R_Bert

[gregintenn]

Yeah, I've been talking about getting one, but haven't yet. I would like one I think.

[R_Bert]

Yeah, I've been talking about getting one, but haven't yet. I would like one I think.

 

This is the one I have - I love it..  Watch for sales this next few weeks.

 

http://www.midwayusa.com/product/852429/competition-electronics-prochrono-digital-chronograph

[gregintenn]

It looks to have good reviews and the price is right.

[Dolomite_supafly]

A lot of people don't think it but a chronograph is just as important as your press or your reloading manual.

A chronograph ensures your hand loads are safe. It also speeds up the load development process.

And with a chronograph you can map your ballistics table without the need to shoot long distance.

[gregintenn]

How does a chronograph ensure your handloads are safe?

[R_Bert]

How does a chronograph ensure your handloads are safe?

I used one to discover that a milsurp powder was 15% hotter than anticipated.

[Dolomite_supafly]

How does a chronograph ensure your handloads are safe?

As Rbert said it verifies the data you have is correct. Most times the published data results in velocity that is lower than advertised but not always. And with certain powders there are large lot to lot variations than can cause problems if you are loading at or near max.

 

Reading primers for pressure is not always the best way because it can vary by the primer used. Velocity on the other hand is a great indicator of where the pressures are. If your data says 3,100 fps is the max with a given powder and your chronograph reports 3,200 fps then you have excessive pressures. And if you are using hard military primers that extra pressure might not show on the primers. Or if you have soft primers they might show what looks to be excessive pressures before you are even close to max.

 

And if you are loading subsonic bullets it ensures the bullet actually left the bore.

[RED333]

 I would be willing to bet your FPS are up from the factory ammo.

I need a chrono as you do.

[gregintenn]

 I would be willing to bet your FPS are up from the factory ammo.

I need a chrono as you do.

My shoulder thought so! Did I mention that little s.o.b. kicks like a mule? The handloads were noticeably louder and had more recoil than the Magtech stuff.

 

A sane person would just shoot the factory stuff, but I want a handload that shoots as good, and near the same point of impact.

Edited November 23, 2013 by gregintenn

[Dolomite_supafly]

My shoulder thought so! Did I mention that little s.o.b. kicks like a mule? The handloads were noticeably louder and had more recoil than the Magtech stuff.

 

A sane person would just shoot the factory stuff, but I want a handload that shoots as good, and near the same point of impact.

That says a lot because Magtech is known for blowing up guns because of their pressures.

[gregintenn]

That says a lot because Magtech is known for blowing up guns because of their pressures.

The listed fps on the box is quite a bit lower than what my reloading book gives for the handload I was shooting.

 

I've shot Magtech ammo in a few different calibers, and have never noticed anything resembling high pressures. I've found their ammo to be very accurate and good in all respects. The brass is good for reloading as well.

 

Never heard that before.

[Dolomite_supafly]

They may have toned them down now. When they first came out their 380 ammo blew guns up. So much so that some manufactures mentioned them specifically in their manuals.