Over Pressure

[25WSM]

If your at the book velocity with way less powder I would check the scale to be sure it reading proper. Might just have a real tight bore.
Shep

 

[live2huntmt]

If your at the book velocity with way less powder I would check the scale to be sure it reading proper. Might just have a real tight bore.
Shep

I re-calibrated my A&D FX120i w/ auto throw/trickle just to be sure!

 

[25WSM]

That's a terrible set up. Send it to me I will send you a perfectly good rcbs 505.

 

[25WSM]

I still use a 10-10 and an M5 that I tuned up. They will weigh down to a single kernel of most powder. But slow.
Auto throw is on my short list.
Shep

 

[1000yards]

I just started developing a load for a CA Ridgeline 300 RUM with 200gr AccuBonds jumping .020" and Retumbo in 1x fired Norma brass and Fed215 primers. I am way below book charge weights and way over pressure and high velocities. This is a new keg of Retumbo...do you think it's just a really hot lot #? Even 89.2 grains is flattening primers, cratering around firing pin, showing both ejector circles, and clicking at the top of my bolt lift. Is there anything that could be causing this other that really hot powder?

The blue line is an average between the two test rounds at each charge weight.View attachment 187933

Could be my alzheimers kicking in but isn't your chart labeled backwards? powder / velocity?

 

[live2huntmt]

Could be my alzheimers kicking in but isn't your chart labeled backwards? powder / velocity?

Yes, it is labeled backwards

 

[Jud96]

Are you sure you're .020 off the lands and not actually in the lands? I've had this happen to me before when I used the old method of coloring the bullet with Sharpie and seating it until I saw marks on the ogive. You can actually be into the lands before you see any marks on the bullet. Just a thought.

 

[live2huntmt]

Are you sure you're .020 off the lands and not actually in the lands? I've had this happen to me before when I used the old method of coloring the bullet with Sharpie and seating it until I saw marks on the ogive. You can actually be into the lands before you see any marks on the bullet. Just a thought.

I think so. I am measuring a .020" jump with both a Hornady modified case gauge and also a RCBS precision mic kit. My OAL is 3.764". My CBTO using a Sinclair comparator is 3.064". My CBTO using the RCBS precision mic is "57". Does this seem right for a saami spec chamber/freebore?

 

[Wachsmann]

Your number seem close to my old 230 berger load but I dont have may book out. I had to single feed at that length.

 

[Jud96]

I think so. I am measuring a .020" jump with both a Hornady modified case gauge and also a RCBS precision mic kit. My OAL is 3.764". My CBTO using a Sinclair comparator is 3.064". My CBTO using the RCBS precision mic is "57". Does this seem right for a saami spec chamber/freebore?

I don't have a ton of experience loading for a .300 RUM, but that seems pretty long for a 200gr Accubond. The simplest thing I'd do is load up a couple rounds .020 deeper and see what pressure and velocity is like. If it doesn't change, try seating another .020 deeper. You'll definitely be off the lands then. This will just see if it's the seating depth causing the pressure or something else.

 

[live2huntmt]

Your number seem close to my old 230 berger load but I dont have may book out. I had to single feed at that length.

Thanks. I am running a Wyatts extended box in it because my other load is 230 Berger OTM Tactical & RL33. I was getting 3040 FPS w/ 94.9gr of RL33 @ 3.815" (.006" jump) and slight pressure signs

 

[cape cove]

I think so. I am measuring a .020" jump with both a Hornady modified case gauge and also a RCBS precision mic kit. My OAL is 3.764". My CBTO using a Sinclair comparator is 3.064". My CBTO using the RCBS precision mic is "57". Does this seem right for a saami spec chamber/freebore?

In my Rem 700 LSS with a 180 gr Accubond I'm just off the lands at 3.745 although I don't use this oal as my magazine only lets me use 3.640. Your #'s seem to be OK.

 

[Wachsmann]

I need to get mine setup with a Wyatt box but for now I'll use the 220 ELDX load that I developed a few years back. I was able to run mag length and with RL 26 ferry dust it was getting 3025fps with very little pressure. It also shot really well. Good enough to make my longest kill shot so far at 761yrds.

 

[Shane Lindsey]

Are you sure you're .020 off the lands and not actually in the lands? I've had this happen to me before when I used the old method of coloring the bullet with Sharpie and seating it until I saw marks on the ogive. You can actually be into the lands before you see any marks on the bullet. Just a thought.

I just used this method.

I did this with every bullet I loaded in my 308 win and was a considerable amount off from what I thought was the lands with what this showed me.