Berger Bullets

[jbs2014]

So I purchased some Berger 77 grain OTM bullets to load in my AR. I also picked up their loading manual. I used Vhit N140, RIMSHOT TAC, and H4895. I loaded everything to the specifications in the manual. When I chronographed each load with my magneto speed I noticed that I was getting 2-300 FPS less than what the manual said I should be getting. So I thought it might be my scale and purchased a second scale but it gave the same weight as the RCBS charge master. I switched out primer types and still had the same velocity issues. I finally contacted Berger Tech support to see what was going on. The individual that I spoke with informed me that everything in the manual was based on quick load (no actual tests) and that was the likely reason for the low velocity numbers I was getting. This is unfortunate because the factory ammo that I have shot that has Berger bullets is so accurate.

Have any of you all had this issue before?

I wanted to do some load development for my 338/378 this weekend with the 300 grain Berger bullets that I have but I am a bit concerned that the data I have from Berger may not be safe. Has anyone here loaded 300 grain Berger bullets in a 338/378? If so what data did you use for your load?

Any information would be greatly appreciated

Thank you for your time

 

[Prieto9000]

I´ve seen the opposite. MV on berger data is way too low compared to my actual MV.
On my .338 LM and my .338 EDGE I´m getting close to 2900 when berger data is close to 2700 using 300gr hybrids. Max load listed by berger is around 89gr of retumbo @105% case fill and I´m stuffing 95gr and it still rattles @ 4.000" COAL

 

[martinakl]

Brass, Primers, and barrel length can all play a role in FPS. 200-300 below posted seems extreme. Super short barrel?

I usually get right around their posted numbers, sometimes a little more. 50+/- FPS. I rarely have the exact component mix used in a loading manual. When seating bullets long, you can usually/sometimes put extra powder in a case. My COAL is always longer than their posted COAL. I think their loading manual mostly uses SAAMI specs. I can usually load over max published loads when seating long. Not easily done in an AR but maybe in the 338/378.

I imagine 4.000" COAL on a 338 Edge is 1/4"-1/3" longer than they're publishing data for. Thats a lot of room for more powder in a fat case.

 

[Trnelson]

IIRC, they utilize a 24" test barrel for their loads. Even if you are using a 24" AR you are going to lose some gas pressure (velocity) due to the DI or piston system that actuates your semi-automatic rifle. You are likely close to spot-on with the velocity you are getting.

 

[jbs2014]

Trnelson I do indeed have a 24" barrel. But why would I be getting normal numbers with factory ammunition out of the same rifle?

martinakl - I have used multiple different primer types and had the same low velocity numbers. CCI did give me a slight increase in velocity

Prieto9000 - Do you think that your numbers may be also due to the book charges being based on quick load. Gotta say though 2900 with a 300 grain Berger is pretty impressive. How did it group?

I guess I will try this weekend with the middle of the Berger recommended load and hope for the best

Thank you all for your time and responses

 

[Prieto9000]

Prieto9000 - Do you think that your numbers may be also due to the book charges being based on quick load. Gotta say though 2900 with a 300 grain Berger is pretty impressive. How did it group?

It works kinda nice. H1000 gave me a little less MV it was somewhere around 2840. Retumbo gets me up to 2872fps with very similar accuracy, I can´t tell the difference. It all comes down to me doing my part.

 

[jbs2014]

Very nice!!! Thank You

 

[Switchback2]

All the books print info on the safe side, I have over a dozen I load for and all are 1 to 4 grains over book max. The books are just a starting point but you will need to adjust and see what your gun likes, May be less May be 5 grains over book
Max

 

[Trnelson]

But why would I be getting normal numbers with factory ammunition out of the same rifle?

Likely a combination of additional factors are at play and contributory to what you are seeing that require further consideration before you throw it in a lake. What you are seeing is normal.
The factory loads are very likely using a different powder, a different bullet with different bearing surface and or jacket hardness, different primer, different brass volume, brass hardness, different CBTO
I sort all my 223 brass into two grain weight lots and have containers full of brass as light as 79g and as heavy as 99g, and 5.56 brass as light as 84g and as heavy as 107g. I keep the 223 brass separate from 5.56 brass, regardless of weight. I use what I want and trade the rest with buddies.
The same load, bullet, primer and CBTO in 79g brass obviously produces a very different velocity than the same load, bullet, primer, CBTO in 107g brass.

 

[tim_w]

What chamber does this .223 have? The length of the throat as well as some of the diameter specs will easily drop pressure enough to see those numbers.

5.56 NATO chamber, Wylde, SAAMI .223 chamber, something custom?

Also the COAL being different combined with a different chamber spec compounds the effect.

 

[jbs2014]

What chamber does this .223 have? The length of the throat as well as some of the diameter specs will easily drop pressure enough to see those numbers.

5.56 NATO chamber, Wylde, SAAMI .223 chamber, something custom?

Also the COAL being different combined with a different chamber spec compounds the effect.

It is a 5.56 chamber. I kept the COAL the same as what was posted in the Berger book

 

[tim_w]

That is likely the issue. The berger I believe is specs for the .223 chamber which has a shorter throat and thus you are likely making a huge jump to the lands and that will drop pressure for a given load and with that vel. See how long you have to seat to touch the lands with that load and if its inside the mag length try 0.015 as a starting point. If you can not fit to mag and want to set it as long as the mag will allow.

This is going to give you more case room and will take more powder but you will also be able to get a good bit higher vel compared to a standard .223 chamber.

For accuracy I like a throat a tad shorter than 5.56 with some of the specs tightened up a bit. The wylde is very close.

Not to say you can not get very good accuracy with a 5.56 chamber you just need to be a bit more judicious in FL sizing and usually need to set the bullets out farther.

Is this an AR or bolt gun?

The 5.56 chamber as you likely know was designed for the M-16/M4 Ar-15 series of rifles for combat and as such had loose tolerances to allow FA and high round count firing under adverse i.e. dirty conditions. Just keep it lubed wet and a it run.

If in a bolt gun I would not want to size down the body until its absolutely needed as it tend to get a good amount

 

[jbs2014]

That is likely the issue. The berger I believe is specs for the .223 chamber which has a shorter throat and thus you are likely making a huge jump to the lands and that will drop pressure for a given load and with that vel. See how long you have to seat to touch the lands with that load and if its inside the mag length try 0.015 as a starting point. If you can not fit to mag and want to set it as long as the mag will allow.

This is going to give you more case room and will take more powder but you will also be able to get a good bit higher vel compared to a standard .223 chamber.

For accuracy I like a throat a tad shorter than 5.56 with some of the specs tightened up a bit. The wylde is very close.

Not to say you can not get very good accuracy with a 5.56 chamber you just need to be a bit more judicious in FL sizing and usually need to set the bullets out farther.

Is this an AR or bolt gun?

The 5.56 chamber as you likely know was designed for the M-16/M4 Ar-15 series of rifles for combat and as such had loose tolerances to allow FA and high round count firing under adverse i.e. dirty conditions. Just keep it lubed wet and a it run.

If in a bolt gun I would not want to size down the body until its absolutely needed as it tend to get a good amount

Thank you, I will try adjusting the seating depth. My rifle is an AR15, stag arms, with a 24" bull barrel.