Developing a load for shooting buddy in his 243 Savage model 11BL with 22 inch, 9 1/4" twist stock barrel. He wants a hunting load so used the Hornaday 87 grain V-Max, new Winchester brass, CCI250, and 43.5 grains of IMR 4831. Various manuals put this load at around 2900 fps and it shoots a very nice .6 MOA when loaded to touching the lands. Trouble is, it's making 3250 to 3300 fps according to my Magnetospeed, and starting to show pressure signs. BTW, this gun has experienced a mild overpressure event before, blown primer, lost extractor, jammed ejector, etc. Bolt got a lot of new parts and trip to the Smith for a thorough check out.

Load development has been a problem for him and me also with this rifle. Seems the throat is very tight, one might say a bit too tight. A lot of scrubbing and cleaning of the chamber and throat, and verifying with my endoscope that it is carbon free, but still a bullet placed onto the lands shows a lot of scraping along the Ogive from the throat, and takes a fairly hard push to get there when using my Hornaday OAL gage.

An OCW load development shows rounds gradually tightening up from 3 moa to under 1 as bullet is moved closer to the lands in .005 increments once we settled on a powder charge, but at touch, the group suddenly jumps up 1 moa and tightens considerably. I suspect a jump in pressure is being seen.

What do you guys think? Is that kind of jump in apparent pressure typical when loading onto the lands, or do we have a dangerously tight throat?

Any thoughts or suggestions from the vast brain trust here would be appreciated!