Over Pressure

[thatguyshm]

It's the CA effect. I have a Christensen Arms classic in 30-06 that gives much higher velocity than book values with most bullets. I just save powder and load to velocity rather than book charges. My take is its the rifle telling me what it wants. I load about 59gr of RL22 with the 180gr Accubond and get 2850 fps. I shot some factory 180gr Sako ammo through that rifle then another 30-06 I have. The CA gave me 2899 fps and the other 30-06 gave me 2740, which just so happened to be the velocity listed on the box.

 

[Shane Lindsey]

It's the CA effect. I have a Christensen Arms classic in 30-06 that gives much higher velocity than book values with most bullets. I just save powder and load to velocity rather than book charges. My take is its the rifle telling me what it wants. I load about 59gr of RL22 with the 180gr Accubond and get 2850 fps. I shot some factory 180gr Sako ammo through that rifle then another 30-06 I have. The CA gave me 2899 fps and the other 30-06 gave me 2740, which just so happened to be the velocity listed on the box.

It is frustrating to load at book mins and get pressure though. Made me question everything...

 

[thatguyshm]

I get you completely, but the biggest thing is every reloading manual states all rifles are different. If you want to look just at the manual, then yes it's annoying. Do you get as frustrated when you use book values and don't achieve the velocity listed? I've seen that more times then I've seen rifles going faster. It's just part of the game. Could be why they don't want you reloading for the rifles.

I just use my manuals to get velocity ranges and make notes of what charges get me there and use that for the most part. Those are my new min/max

 

[NW Hunter]

The $90 Teslong has a bore rod with the camera attached to the end.
It makes it easy to rotate the god in your bore to get a 360 degree view.

Aahh rod not God.
Heesshh

 

[MTGEEZER]

Aahh rod not God.
Heesshh

A little more "food for thought" on my CA Mesa: when I shot Big Red's ELD offerings, the primers were absolutely flattened and velocities were 75 to 110 fps higher than listed on box!

 

[shooter7]

A little more "food for thought" on my CA Mesa: when I shot Big Red's ELD offerings, the primers were absolutely flattened and velocities were 75 to 110 fps higher than listed on box!

I have a Mesa 300wm that does some weird stuff. My powder charges typically beat the book velocities by 150-200 fps. I did once lock the bolt with a powder charge that was 1.5 gr below book maximum.

 

[Tommy T]

We are loading my 30 nosler and we are using the RL 22 powder with wlrm primers with 210 ABLR. bullets and nosler brass and they are shooting a 2 to 3" grouping at 500 yds. And it shoots great we are going by the nosler loading book as well . I only use RL 33 in my 338 lapua CA rifle

 

[kiwi49]

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.

Thank you for insight.
My OLD Omark actions may not give me as much 'feel' as the action you're using, but the methodology makes a lot of sense.
I'm using a Hornady modified case and a machinist friend made the rest of the tooling for me.
Along with the standard Hornady CBTO setup, I've been getting variations of 0.003"-0.008" in CBTO length.
One barrel (13T), was reset and rechambered in 1994, the other (10T), has only had 275 rounds (previous owner + me), through it.
The 'old' barrel still shoots around 1"/100yds, the newer barrel hasn't settled in yet, but the previous owner (better glass than I can afford), was shooting in the top 3, out to 1,000yds.
Once again, thanks for a potentially better method than I'm currently using.
Cheers from New Zealand.

 

[Betarider]

It is trimmed to min, neck turned, chamfered and de-burred. Also dry lubed to inside of neck. Necks are expanding.006" when fired.

Where can I get a $50 borescope?

Amazon had one from China that was slightly bigger than 7mm as would not fit mine but bigger they had no problem seeing the bore. And was $19.95 and free shipping with prime

 

[dougduey]

I own a CA Carbon Classic in 338 Lapua. I had the same problem with Retumbo and 250 gr bullets. CA has tight manufacturing tolerances, so the chamber is tight. It never had an issue with new brass or factory ammo. I would get a sticky bolt lift using 1x fired brass, FL resized bumping back the shoulder 0.002". What I ended up finding out was my Lapua brass was too thick in the neck. I switched to Nosler brass and the problem went away. I neck turned the Lapua brass to get it to work too. It also helped that I switched to a Redding Type S bushing die.
Take a piece of your fired brass that was showing pressure and see if a bullet will slide through easily. If not, it's the brass causing the problem.

 

[DJ Fergus]

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

I've shot 200 grain accubonds in 300 win mag. They are good shooting bullets but from my experience, they build more pressure than say: target bullets of similar weight. Thr jacket on the 200 gr accubonds is thick & the lead is somewhat harder. It has a fairly long bearing surface. I could push 208 elds at same speeds with less pressure. The 200 gr accubonds should be fairly jump tolerant also. More jump should get your pressure down some amount. I've never run the regular 215 primers but I have used alot of 215 match primers. They flatten way more easily that any other primers I have used. I sometimes substitute 250 cci primers for the 215gm and I get the same velocities at the same charge with out the flattening of the 215gm.

 

[Warbird2006]

I loaded mu 338 Lapua with Retumbo and it went flattened all my primers, I was not been on maximum. Cases split during 2nd shot. I switched to H1000 no problems. On the other hand Retumbo is great in my 257 Weatherby

 

[WYO300RUM]

A little more "food for thought" on my CA Mesa: when I shot Big Red's ELD offerings, the primers were absolutely flattened and velocities were 75 to 110 fps higher than listed on box!

Thanks Tom.
Factory Hornady 143 Hunter and 147 match don't show or have any signs of pressure in my CA 6.5 PRC Ridgeline . I have but haven't yet shot any other loads in it yet. Good thread info to remember .