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Anyone own a 7mm 300 Win Mag?

 
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  #64  
Old 10-21-2010, 05:11 AM
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Re: Anyone own a 7mm 300 Win Mag?

In regards to the throat on the rifle, how would one go about getting the throat on my gun to match a 180 VLD? As of now it was chambered using a ordinary 7mm-300 WM chamber reamer and I dont know what the throat angle is...
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  #65  
Old 10-21-2010, 05:27 AM
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Re: Anyone own a 7mm 300 Win Mag?

The person who reamed the rifle should be able to contact the reamer manufacturer, obtain the drawing and be able to tell you about the leade angle, what it was designed to suit.

If you have a long COAL allready, there won't be much room for re-throating and you will find that many smiths don't like re-working existing barrels. If you are having trouble obtaining optimum accuracy with the 180gr VLD, perhaps re-look into load development for a start.
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  #66  
Old 10-21-2010, 09:42 AM
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Re: Anyone own a 7mm 300 Win Mag?

Im not calling anyone a liar I'm just saying I dont understand how you guys are getting these velocities 3175 with 77 gr h-1000 and berger 180's. I dont have a lot of experience but Im just running numbersd and comparing data. So tell me how I have it wrong I guess. Heres is what I have.... Comparing other calibers that are neck down according to the nosler 6 reloading manual in a 308 using 150 gr ballistic tips with a max charge of RL15 46.0 you get 2958, with a 7-08 using 150 gr ballistic tips with a max charge of RL15 41.5 you get 2802. Comparing a 300 wsm vs a 7mm wsm. With the 300 wsm using a 150 gr bullet using a 150 gr BT using a max charge of RL 19 69.5 you get 3242 fps. Using a 7 wsm using 150 gr BT using a max carge of RL19 64.5 you get 3129. SO looking at a 300 win mag with a 24" barrel using a 180 gr BT over max charge 77 grains of IMR7828 ( sorry no info in there about H-1000) you get 3048 fps. So I just dont see how you get all that extra velocity? Is it the barrel length? Also looking at some other calibers like the 7 STW it can only achive in a 26" barrel using a 175 partition spitzer a max velocity of 3042 75.0 gr of retumbo. The 7 RUM using the same 175gr bullet, barrel 26", can only achive 3164 with a max load of 92.0 gr of Retumbo! So the 7-300 using 77.0 gr can do more than the 7 RUM , which is using 92.0. I know some cases can be more effiecient but wow. Again Im not calling anyone out. I just dont understand how its possible. I believe the people who have posted I just want to understand. And when I understand I will be probably be rechambering a rifle to this 7-300 because it sounds AMAZING! Thank you.
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  #67  
Old 10-21-2010, 12:08 PM
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Re: Anyone own a 7mm 300 Win Mag?

So again Im not saying its not possible but I just dont get it I guess. Looking in the hornady book now 7th edition. In response to this statement 162 AMAX

162 gr AMAX
79 GRN H-1000
Rem Brass
CCI 250
3340 AVG FPS

In understand this is in a 28" barrel but in the manual a 7mm RUM in a 26" barrel using H-1000 at a charge of 87.3 with the 162 AMAX it only reaches 3100 fps. And a 7 RUM with 175 gr SP bullets with the same 26" barrel using a max charge of H-1000 at 87.3 gr only reaches 3000 fps. Compairing a weatherby 300 to a weatherby 7 using the same weight bullets the 7mm loses velocity as well. I just dont understand how you guys are picking up about 200 fps by necking down the 300 win mag and how with 77 grains of power you are achieving far more than the rum can with 87.3 gr of the same powder.

Taken from Hodgons website 180 GR. SPR Hodgdon
H1000 .308" 3.285" 76.0 gr 2883 fps81.0C gr fps 3042
So it doesn't state what barrel lenth these are taken with but from what I have found from looking it seems that just by necking down you can achieve similiar velocities by necking down from 300 to 7mm with slightly less powder so one could assume that 180 7mm vs 180 30 cal with the same charrge the 7mm would pick up velocity. But according to this with 81 gr of H-1000 using a 180 gr spr the 300 win mag reaches 3042 fps. So Im just confused how you guys get this 3175 with H-1000 at 77.0 gr pushing a berger 180 gr. Again Im not calling anyone a liar in fact Broz I have read many of your post and found that you have always seemed to speak honestly and without embellishment. I have always given your post a lot of credit. This is why Im so confused. I dont have much expierence with cartridge wildcatting or longrange hunting so I fall back on data that I can read and interpret, this time it just doesnt fit for me. I sure that these claims are accurate I'm just not sure how. What am I missing?
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  #68  
Old 10-21-2010, 12:32 PM
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Re: Anyone own a 7mm 300 Win Mag?

Those manuals are sissy and to boot sids gun is throated long so it has more case capacity hence more speed.
Take for example the 264 winmag which i have plenty of experience shooting. IMRs site gives these numbers for H-1000
140 GR. NOS PART Hodgdon H1000 .264" 3.260" 55.0 2810 58,600 PSI 58.5 2900 61,800 PSI Now i dont shoot the 140 part. but i am shooting the 140 amax at 69.0 grains of powder which is 10.5gr. more than what imr says is max!
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  #69  
Old 10-21-2010, 01:10 PM
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Re: Anyone own a 7mm 300 Win Mag?

Quote:
Originally Posted by pyroducksx3 View Post
What am I missing?

The barrel length has a lot to do with velocity, especially in large magnums. If one cartridge shoots around 3000 fps with a 24" barrel, the same cartridge could very well shoot almost 3200 fps with a 28 1/2" barrel. Personally, I don't trust my crony farther than I can throw it. I get my velocity numbers using drops and Exbal.
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  #70  
Old 10-21-2010, 01:10 PM
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Re: Anyone own a 7mm 300 Win Mag?

Ok even if the manuals are sissy it doesnt change the fact that at from the hodgens website with a charge of 76 gr of H-1000 they only recieve a velocity of 2883! So even if you pick up velocity by necking down and even if this was based on a 24" barrel, saying that you pick up 300 by necking down to 7mm and adding 4inch of barrel and 1 gr of power seems far fetched. I also compared data from the 300 win mag vs the 300 wsm and everything stays pretty consitant.So by comparing the 7mm wsm to the 7-300 win mag you would think you would get resonably equal result as well. But comparing the data a 7 wsm with a 162 gr amax reaches 3000 fps , this is with a 24 " barrel. Like I said there is so much to consider that I just dont know. Reviwing the data i can see that the 7-300 win mag has much more capasity than the 7mm wsm. The 7 wsm at 69.0 gr of h-1000 is compressed and obviously doesnt come close to the claimed 3300+ with 162 amax. But then again looking at hodgens website the 300 win mag using 84.0 gr of H-1000 and a 165 gr bullet only reaches 3117 fps, this far is 6 grains below the stated 79 gr and reaching 3340 with a 162 gr 7mm amax. Again I understand that the barrel length is not given for the hodgen data, so lets assume it 24". Looking at reloaders bench there is so no data for a 7 wsm using a 180 vld of anyone even getting much above 3000 fps using a 24" barrel. And looking at data ofthe 300 win mag 185 gr lapua sentar over 78.5 gr of h-1000 in a 26" barrel only reaching 2910 fps, that a 265 fps difference. Looking at reloaders nest people are getting a 180 gr bullet in 26" barrels in the 300 win mag using H-1000 up to the low 3100's but its in the 80.5-83+ range. I just have no expierance with wildcats so the more I look at it the more I get confused. At one point I read something I see its possible and then something else makes me doubt it.
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