Turning a t3 300wm into a 300-7mm

[Sandstrom22]

Hello everyone, new to the forum. I have a tikka t3 300 win mag that I am currently shooting. Have about 400-500 bullets through it. i was thinking about trying out a new barrel but I am not component in this area on the capabilities of this action and rifle model. I was thinking about changing the rifle into a wildcat 300wm-7mm which means a 300 case pushing a 7mm bullet. Correct? Am I a fool for attempting this or what. Currently running 2880/2890 FPS at the muzzle with 210gr VLD on 67 grains of 4451 on the factory barrel on my 300 win mag. I still would like to keep the ballistics up enough that 600 plus yard shots are manageable on a elk or mulie. To make a long story short, am I wasting my time and money for what I already have. I want a long range gun. But think I mah already have it.

 

[BEEMAN]

I think you already have a long range gun. As long as you have the twist to stabilize the 210-215 Berger. How does the gun shoot? If you can find some H1000 and 215 Bergers; give that combo a try. I think you will be impressed. The 215 is one awesome bullet. Try it at about 30 to 40 thou off the lands to start. Unless the gun doesn't shoot well, I wouldn't re-barrel it.

 

[Sandstrom22]

I can't get it to group less than 1.25" with the h1000 or retumbo. I've had some good luck with this 4451 though. In getting about 3/4" groups at 200yds. I can't get my coal length longer than 3.354 or else my magazine won't cycle the bullet

 

[BEEMAN]

Might need to single feed it. The 215 in both my 300 RUM and 300 WIN shoot incredible. Just put together my 300 WM and load development was done in 12 rounds. Every charge weight I tried produced one ragged hole groups at 100 yds. Shoots well under half MOA out to 700 yds if I do my part. Haven't had a chance to shoot it farther than that. Try some closer to the lands. Like I said 30-40 thou off seems to work. Others have had good luck much farther from the lands as well. But in the rifles I have tried 30-40 thou off has always worked. If it works you could put in a extended box. Be cheaper than a barrel, reamer smith etc.

 

[Sandstrom22]

I'll give it a try. Thanks for the info, I will report back. Thinkin I'll poke out to 600-700 tmmrw with the CDS system on my vx3

 

[FEENIX]

I think you already have a long range gun. As long as you have the twist to stabilize the 210-215 Berger. How does the gun shoot? If you can find some H1000 and 215 Bergers; give that combo a try. I think you will be impressed. The 215 is one awesome bullet. Try it at about 30 to 40 thou off the lands to start. Unless the gun doesn't shoot well, I wouldn't re-barrel it.

+1! IMR 7828SSC, H4831SC, and Retumbo are good too!

 

[Sandstrom22]

Wow, didn't think my lands were too far out from what I had been loading. I loaded a empty shell with a very light neck tension into the action and slid it in until the bullet was all the way in and bolt was down(took a little bit of force but it worked). I tried to eject the shell, but the opening on the action was not long enough. So I had to release the bolt and pull it out where the bullet shroud comes to the action. Measure it on the caliper 3.684"....thinking I did it wrong I repeated the same thing. Same length at 3.684"...versus the factory coal at 3.34"... Anyone else with a 300wm t3 seeing the same coal length to find the lands? Or anyone familiar with this length on their rifle. The 210gr VLD is sitting out pretty far on the case? I had been loading my reloads right at 3.35" so that I could get them compatable with my clip and still eject them if I didn't discharge the round. I plan on shooting a handfull of these next weeknd. The loads I've been shooting I'm getting a 1/2"-3/4" group at 150 yds but shot it yesterday at 600 was getting about a 8" group. Thinking maybe my vx3 4.5-14 is partially to blame because Its a pain to hold on the Orange bullseye but hoping this longer bullet tightens em up.

 

[Rick Richard]

As advised, keep what you have. In my opinion the 300WM with the 210 or 215 is plenty for what you want to do.

I also agree that .030 -.040 off the lands for the 215 will probably give you good results. In the lands to .020 is usually a good spot for the 210s