Choosing COL?

[Rollins]

Ok guys need your help again. I am reloading for a ruger American 450bm. Unfortunately there is not much data published on this round and what is seems to focus on hornady fx bullets.

My question is how to pick min col? I had some good loads for for my 230 hp bullets with col of 2.10 as mentioned by some here and appear to work good from initial testing.

However a person on cast boolits forum sent me 100 rounds of 250 grain jacketed bullets he makes himself.
However I can find no information on 250 grn soft tip loads. It is all the xp tip rounds, which from their design are longer per weight than soft tip or the hp points I can get affordable.


Looking through posts on here and youtube,I see many different cols for different bullets and want to know how to select the correct one instead of having to ask someone what they use for each load. So how do you experts figure it out?

For the 250grns I guessed. I tried the col for the hornady in that weight( I think 2.20) but it was barely in the case, so I then went with 2.15 as it was a bit heavier than the 230s at 2.10. I didnt want to seat them too deep. From what I have read seating to deep can compress powder and cause over presure and problems.

[Bmt85]

Really depends on the bullet and what you want out of it. I usually try to get one caliber in the neck (.45ish). The more inside the neck, the better the hold, but it restricts case capacity. How much bearing surface do these bullets have?

I have a feeling you are going to be loading them similar to the 230gr HP's.

[Rollins]

Basically plinking fun loads. Though if they do really well I might see about using them for deer. 250 grains with a soft lead tip should put down a white tail pretty well.

In the past for reloading my 308 I just matched the bullet with what the published data said and went on my way. I have heard some people mention using the caliber to determine how much to put in the case like you mentioned.

My fear was juat that if I pushed the heavier bullet to far into the case it could cause compressed loads and or pressure spikes, and if I put bullet to far out it could cause feeding problems or push bullets into the lands.

I have seen some people put really short col of like 2.00 or so but I know it varies on bullet length shape etc.

So it sounds like if i put the caliber size as length into case and keep it below the max col I should be ok?

[Al in Mi]

Far from a expert but first thing I do for any bullet if make a dummy round with the bullet seated into the lands. From there I'll figure a oal for my bolt guns, as a rule, I seat .050 off the lands and work up loads from there.

[Rollins]

Thanks Al. But what about the minimum col? For max what you say makes sense though I heard the bushmaster has enough freebore that touching the lands is not a problem usually.

But for min col how do I determine that? Like if I have a bullet and it is below the max Col, how do I know how short i can safely make it? I dont want to put the bullets too deep or not deep enough .

[Al in Mi]

I'd go with what BMT85 said, one caliber deep.

[Bmt85]

Well, I guess minimum for any bullet would be when the ogive is almost at the case mouth. When dealing with a new bullet that doesn’t have load data, you can look at similar bullets to gauge your oal and powder charge. Thing is, there are a lot of variables at play, so it’s not going to be the same. Even regular load data doesn’t work all the time because of different chambers and bores. Then you have differing components and even variations from lot to lot in the same components.

So trying to get someone to tell you exactly what you need for min or max for a bullet that no one has played with is impossible. We can try to give you a starting point, but you’re the guinea pig here. Quickload will usually give you a much better idea for powder charge, but you need to input some info.

With that said, I don’t think this one will be that hard to figure out. Need to know what the bearing surface of this bullet is.

[Al in Mi]

Snap pic of that bullet if you can.

[Rollins]

Measured the bullets length and I get .6495-.6500 for the 250 grain soft tips. For 230 grn hp I get .6350-.6345 long.

Edit for some reason I cant upload pic.i select add attachments and select my pic, but it wont add it.

[Bmt85]

Need the measurement of the bearing surface. Its the length of the bullet that's .451

I've been having problems with sites program to add pics. If you store the pic at flickr, then choose share and medium size, it will give you a link that you can post. That link will show the pic on this page.