New Rifle and need some input....

[Cruizin]

Well got my new rifle and have been working up some loads trying to get up to 3000 fps with the 300smk. Here are some specs on the rifle with some pictures.

My gunsmith calls it the 338 Tejas but its basically the 338 Edge AI.
McMillian A5 stock
Rem 700 Action converted to single shot.
Rock Creek polygonial barrel 1-9.25 twist 29.25" long
DE Brake
Nightforce 5.5-22-56 glass

I got about a 5 grain in water increase in case capacity. I'm working on a getting a comparision picture.


I have a really accurate and very low ES load worked up, but I am not able to get the 3000 fps.

Here are the details:

Rem brass
cci250 primers
.030 off the lands
300 gr. SMK
95 grains of H1000
bullet seated at 4.040" COL

I am looking for suggestions here. This load is super accurate and ES was 3-4fps for the 2 strings I have fired thus far, but I'm only at 2830 fps. This was 15ft from the muzzel at about 6000 ft elevation and 60­° outside.

I loaded up to 95.5 and didn't see any pressure signs yet but accuracy wasn't improving and the fps didn't seem to go up that much either. With 95.5 gr I was only getting 2850 fps. Could this be correct? I'm using a new CED but it seems to be very consistent and it was ideal conditions this morning so I tend to trust the readings.

I was expecting more out of this rifle. I'm looking for other powder suggestions and other things to try.

I did use a neck bushing that was not ideal because I didn't have the right size at the time. It was giving about .005" neck tension. If I loosen this up to .002" or .003" do you think I could see an increase in velocity of say 100fps?

What would you guys recommend trying next? Powder suggestions and starting load anyone? Would it be worth while to try other primers? I was thinking of trying moly bullets but not sure. I'm just excited I have 2830 and a really accurate load. Just picked up the swaro range finder so I'm headed out to kill some rocks tomorrow morning.

Let me know what you think.

Thanks,

Not so Cruizin,

Cruizin

 

[Cruizin]

Here is a comparision pic...

 

[Cruizin]

If this helps at all my fire form load was 92 grains of H1000 and 2750 fps.

 

[landcbeitner]

That's a beautiful rifle! Sorry, I can't help you with your question.

 

[glassman]

It was giving about .005" neck tension. If I loosen this up to .002" or .003" do you think I could see an increase in velocity of say 100fps?
Cruizin

Here are my thoughts on this:
A heavy neck tension will give you more pressure, hence more velocity.
So if you lighten the neck tension, then you have less pressure, so hence less velocity.

If it was me, I would go up in 1 gr increments instead of 1/2. A 1/2 gr increase is not really going to show you much on a big casings. If on a smaller casing such as a 22-250, then 1/2 gr jumps are the best.

I can't really tell you anything about the cal., but just keep watching for the pressure signs...checking the headspace as you go along and watching the primers.

When I got into shooting moly bullets, I found out a few things that needed to be done in order for them black bullets to shoot good. It was that I needed more neck tension, so I removed about 1 thousands from the expander ball and that was just enough to give good pressure and excellent accuracy.

 

[royinidaho]

Hmmmmm, very interesting.........

Being a velocity hawg I'm amazed I'm going to respond in this manner.

Several years ago I would have responded completed the opposite.

If your "first" two strings, however long, provided the results you posted, I'd stop right there.

You have a load that has enough velocity to get the job done as far a you can hit and that will be a surprising long ways, as times go on.

The load is accurate, and seems very case friendly with is worth a lot. Besides cost saving, for us penny pinchers, there is easy extraction and uncomplicated feeding problems which can become an issue when hunting at certain times.

I would have thought that the bore configuration would have allowed for a bit more velocity.

I used to be hooked on the 3000 fps mark, but have since settled for close, but opted for the superior accuracy.

Additionally, I feel that you will gain more by shooting for drop chart development rather than shooting for load development.

Just my penny's worth.

Also, a sweet rig!

 

[James Jones]

I agree with roy about the speed thing the extra 150fps your seeking isin't gonna amout to a hill of beans on an animal though it may make a noticable differance in drop and wind drift but unless your using a lazer or layed out markers and wind flags I doubt it'll make that big of a differance.

I'd suggest that if it is the speed that you have to have , either switch to a differant bullet (maybe the 265gr wildcats), maybe try a differant powder , but asking 3000fps from the RUM case with rem brass is alot and you will likley loose ALOT of case life and the accuracy will probably suffer also.

I know that I'll gladly give up 150-200fps if I gain 1/2-3/4 MOA group reduction.

 

[gamedog]

+1 Roy and James. Velocity numbers don't mean squat in distance shooting. Accuracy and consistancy will do much more for you.

 

[Varmint]

I agree with every one else here. but if you want more vel. I would try Retumbo, or US 869 they are slower powders.