7mm08 H335 and Primer/Bullet Questions

[Leaky Waders]

Hi,

I'm relatively new to reloading - thus far mainly reloading 45 long colt/schoefield and 28 gauge shotguns shells.

I'm starting to accumulate some 7mm08 rifle brass and would like to start playing with that round next.

Right now I have winchester large rifle primers, Speer 130 gr btsp, Sierra 120 gr spitzer 1900, and H335.

When I look at the data in the speer relaoding manual #14 - a magnum rifle primer is recommended with all H335 loads.

When I look at the hodgdon 2009 manual, all the data is based upon remington 9 1/2 primers

Also, neither manual has any data on the sierra 120 gr spitzer...the hodgdon does have data on a 120 gr nosler ballistic tip. My speer #13 manual does have the bullet listed but no data for H335.

So...do I need magnum large rifle primers or not?

Do I just use the data for the 120 gr bullets interchangeably or do I use the next heavier weight bullet data for the sierra 120? (Which would be 130 gr sierra hollow point boat tail)?

Thanks for the feedback.

 

[loadedround]

Hey Leaky: If a listed load recommends a magnum primer, that is the way Speer ballisticians developed that load and I would follow their advice. Having said that, someone could substitute a standard primer assuming you are not working with maximum loads, and observe differences in velocity and accuracy. Many experienced reloaders do change types and makes of primers in search of the most accurate load. You must know how to read all pressure signs when changing components. Stick with the manual.

 

[NavyLCDR]

As far as the primer goes, I've loaded 8mm Lebel with H335. I imagine the 8mm Lebel case is probably a lot higher volume the 7mm-08, but my experience is that the magnum primer was required to ignite the powder. When I used standard large rifle primers I got squibs and the powder came out as an orange, chalky like substance. I would go with the magnum primer, in your case.

Given that pressure listed for 120 GR. NOS BT at both min and max charges of H335 are below the pressures listed for 130 GR. SIE HPBT at both min and max charges, I would say that it would be perfectly acceptable to use the 120 GR. NOS BT load data as written in the manual for your 120 GR Spitzers.

If it were me...I would use a magnum primer and the data in the book listed for the same bullet weight.

If you can, you might want to try a 4350 powder. It will fill the case, and I think you will have better luck with it.

 

[NCsmitty]

My personal choice is to use a magnum primer with spherical (ball) powder, regardless of the load data recommendations. H335 is a ball powder, and as such, can be a little harder to ignite, compared to extruded powder. Under all atmospheric conditions and temperatures, magnum primers ignite the ball powder consistently.

Some may disagree and say that they use standard primers with ball powder without issues. That's fine, but I've been doing this reloading thing for a while, and I know what works for me.

On your bullet choice, as long as you have a good COAL that doesn't put you into the rifling, just concern yourself with the bullet weight and not bullet brand when working up a load.

If you decide to flirt with heavier bullets, like 140gr-150+gr, consider using a slower burning powder as NavyLT mentioned, or something like Alliant Rel-19. Look over your manual and select a powder that works better with heavier bullets.



NCsmitty

 

[oneounceload]

In MY 7-08, the favorite loads use WIN760 and standard primers with a variety of Speer or Sierra bullets in the 120, 140, 145 range

 

[Leaky Waders]

Thanks for the feedback. Yeah I was thinking about just getting some different powder. I have the H335 for reloading both .223 and 7mm08. The manuals required less H335 as compared to other brands in 7mm08. So I figured that I could get more reloads per lbs of H335 versus other powders.

What is the heaviest bullet that you've put in a 7mm08? It seems that 140 grains are the common loading for hunting. Is there any advantage of loading 165 or 175 grain bullets?

 

[10pointman]

I've used 4895,4007ssc with great results.......140gr bullets.....one ragged hole at 100yds

 

[NCsmitty]

Is there any advantage of loading 165 or 175 grain bullets?

The problem with all the 308 case based cartridges is the short neck, and the fact that most are chambered in short action rifles requiring a limited COAL to work through the magazine.
Longer heavier bullets that are held to the short COAL, infringe dramatically on the usable powder space, and limits the performance of those cartridges somewhat.
IMO, the 140gr bullets achieve a good performance balance in the 7mm08.

The 280 Remington and 7mm Remag are a much better choice for shooting the heavier 7mm bullets that are over 160gr.



NCsmitty

 

[GooseGestapo]

Magnum vs. Standard primers w/H335 or other ball powders.

Depends on what part of the World you live in.

In S.E. USA, where temps run from low-mid 20's in winter/hunting seasons to upper 90's and low 100's in summer, the standard primers work fine.

However, in upper and Western US where winter temps can run below 0-deg., magnum primers are more desireable to a down-right must. Hence, the powder manufactures and Data producers utilize the magnum primers.

Personnally, I've gotten excellent results in the 7mm08 with standard Federal, CCI, and Winchester primers. Especially with BLC2.

 

[oneounceload]

I used to live out West and never used magnum primers in my 7-08 - hunting was done in temps from 0-60 degrees at elevations ranging from 4500 to 8000' no issues........

I tried loading 160 and 275 - just never was accurate in MY gun. The 130, 140 and 145 all shined. 760, 4064, 3031, and similar all gave good groups, with 760 working the best for me.