7 SAUM Extended COL, Nosler 175 ABLR or Barnes 168 LRX, Retumbo

[7mm Man]

Does anyone have experience with handloading for a approx. 2.95" COL with 175 ABLR or 168 LRX? Especially with Retumbo? I have ran the 175 ABLR with H1000, but now that Retumbo is around I want to work that out. Nosler says 63.5 max with 175 and Retumbo but that is with a 2.825" COL. I have a 24" Carbon Six R700 shouldered prefit on a R722 I stripped and trued action, upgraded to a Mack Brothers magnum bolt. She sits in a AG composites Alpine Hunter stock with trigger tech special trigger. I was only able to get 2700 fps with 59.0gr of H1000 on a 175 ABLR. I ran it up higher but accuracy fell off. I have put together loads up to 64.0gr of Retumbo for the 175 ABLR with crushing only beginning at the 64.0gr. I wonder should I try up to 64.5gr? If I could at least get her up to 2850 with the 175 ABLR with great accuracy I might leave with half a chubb. At this time I have no testing with the 168 LRX in the 7 SAUM, but I was able to get 2870 fps with the Hornady CX and H1000. I had a 70-80 fps jump in velocity around the 150 round count. Thanks in advance.

 

[wind gypsy]

Retumbo is starting to get a little bulky at max charges for a SAUM with heavies loaded under 3" COAL. I've loaded up to 64 gr h1000 with 175 eldx/175 EH in a long throated, long seated SAUM though without issue but that's getting up there in pressure. So in that use case, i'd be comfortable with 64.5 retumbo but not sure how that translates to your situation if you have a SAAMI throat.

 

[7mm Man]

Retumbo is starting to get a little bulky at max charges for a SAUM with heavies loaded under 3" COAL. I've loaded up to 64 gr h1000 with 175 eldx/175 EH in a long throated, long seated SAUM though without issue but that's getting up there in pressure. So in that use case, i'd be comfortable with 64.5 retumbo but not sure how that translates to your situation if you have a SAAMI throat.

I have a SAAMI throat, but so far I have been constricted by the Hawkins precision hunter magazine more than anything. COL being about 2.95" max, otherwise tips will start rubbing and affecting feeding. I milled out some of my action to get them to feed in pretty smoth. I also forgot to mention I am using CCI BR2 LRP. I have seen better consistency than the mag primers. I have a couple pounds of Magpro, which always produces good velocities, but I am always apprehensive about the possibility of temperature sensitivity. I could try that as well. I had hoped for a little more velocity than what I have been getting but in hind sight we are only talking an extra 0.15" of room for extra powder when looking at the Nosler load data. In the end it mirrors my 280AI. I should of went with a XM action and went with a longer throat. Oh well, it allows me to have another project. I appreciate your input Wind Gypsy.