Suppressor Causing Groups to Grow

[Harvey_NW]

How so?.... I mean the idea is that OCW with a large enough sample size you'd be able to gather enough data for a good statistical analysis of the performance and be able to extrapolate what the standard deviations would be for group sizings.

When OCW is taken to a statistically valid sample size the groups either average the same, or the lower powder charges have less dispersion. Nodes don't exist.

 

[Lunchbox37]

When OCW is taken to a statistically valid sample size the groups either average the same, or the lower powder charges have less dispersion. Nodes don't exist.

Ahhh thats making sense.

 

[Lunchbox37]

So just an update on this topic.

I got selected to qualify for a CPW dispersal hunt in southern CO, so I put a pause on the troubleshooting with this ELD-X load and focused on developing a Non-Lead load (ended up using Barnes 168gr TTSX)

The Barnes load was sitting on top of 54gr of H4350 in Lapua Brass w/ CCI 200’s to light it off. MV was 2605 FPS, SD of 10 and ES in the mid 20s. This load shot really well for me (.5-.65moa for 5shot groups).

After qualifying last week I decided to test them thru the TBAC ultra7…. Expecting the groups to open up like they did with the ELD-X load, but they didn’t! Shot .7 moa . I didn’t have my chrono with me to see what was going on with the free bore boost etc, but I was still amazed.

This gives me some hope that dropping the powder charge may be the ticket to getting the ELD-X load to group better. Hoping to get out to the range soon to test the theory.

 

[longrange13]

So just an update on this topic.

I got selected to qualify for a CPW dispersal hunt in southern CO, so I put a pause on the troubleshooting with this ELD-X load and focused on developing a Non-Lead load (ended up using Barnes 168gr TTSX)

The Barnes load was sitting on top of 54gr of H4350 in Lapua Brass w/ CCI 200’s to light it off. MV was 2605 FPS, SD of 10 and ES in the mid 20s. This load shot really well for me (.5-.65moa for 5shot groups).

After qualifying last week I decided to test them thru the TBAC ultra7…. Expecting the groups to open up like they did with the ELD-X load, but they didn’t! Shot .7 moa . I didn’t have my chrono with me to see what was going on with the free bore boost etc, but I was still amazed.

This gives me some hope that dropping the powder charge may be the ticket to getting the ELD-X load to group better. Hoping to get out to the range soon to test the theory.

As others have said nodes don’t exist and dropping a charge won’t change things. Swapping powders and bullets are what make a difference with a rifle. You also need a consistent bullet release. Similar to the results with the barnes I would try a few different bullets. Your rifle does not like that particular eldx. You’ll be better off abandoning it than continuing to chase things.

I tested this theory recently with a new 7prc. Rifle was built with no expense spared. I did some Initial bullet test with middle of the road powder charges. I shot the 180 eldm, 175 eldx, 139 barnes lrx, and 180 berger. The eldm shot around 3/4 moa. The 175 shot around half. The 180 berger shot around half, and the barnes shot around 3/4. While I shot through my brass the first time I wanted to see if I could average around a .5 with the 180s. I tested 4 different powders and numerous charges and seating depths. Toward the end of my brass I settle with what in theory should be the best combination. I shot a 20 shot group, 4 at a time letting the barrel cool between strings. In the end my groups with the 180s were right at 1”. Everything I did, did not change a thing.

I then swapped over the the eldx with my once fired brass, ran it up to pressure, backed it off a grain. Shot my 20 shot group, and I was right around .6. Point being I did nothing special with the bullet it loved. It took 30 shots to do load development and hammers now. I have consistent brass and a bullet the gun likes. Case closed.

 

[Holycross07]

I saw a very similar situation with a rifle I own when a suppressor was used. I changed bullets and power and it is shooting even better than the load I had group well before I put the can on.