Valmet M78 “MCP” 30 round – .308 Magazine
About this product
The Valmet M78 "MCP" magazine is a 30-round detachable box magazine chambered for .308 Winchester / 7.62x51 NATO, built specifically to feed the Valmet M78 rifle. It's made by Max Capacity Products, a small manufacturer that fills the gap left when factory Valmet magazines dried up decades ago. This is not a universal AR-10 or FAL magazine — it's cut to the M78's specific feed lips and lock geometry, which is exactly why M78 owners search for it by name instead of buying whatever .308 mag is cheapest.
What is it used for?
It feeds the Valmet M78, a Finnish-pattern battle rifle chambered in the full-power .308/7.62x51 cartridge. Owners buy it to replace worn or missing factory magazines, to have spares on hand for range use, or because their rifle came with only one magazine and they want a second. It's a functional parts-and-accessories item, not a display piece.
How does it compare to standard-capacity M78 magazines?
At 30 rounds it holds noticeably more than the smaller factory-pattern magazines most M78s were issued with, which means more weight and length hanging below the receiver. That changes how the rifle balances off a bipod or in a sling, and a longer magazine limits how low you can get behind cover compared to a shorter mag. Some shooters keep a short magazine for maneuvering and this one for the range or a fixed position.
What fits it?
It is built to fit the Valmet M78 rifle's magazine well. Because the M78 shares lineage with other Valmet-pattern rifles, some related receivers may accept it, but we can't confirm cross-compatibility beyond the M78 itself — check your rifle's magazine well dimensions or ask us before you order if you're not running an M78.
Who is this not for?
Owners of any other .308 rifle — it will not drop into an AR-10, FAL, or PTR-91. It's also not an option for residents of states that cap magazine capacity below 30 rounds: California, Colorado, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York, and Vermont all restrict magazine capacity by state law, with several capping at 10 rounds. Know your local law before you order.
Is it worth $180?
The price reflects scarcity, not materials — the M78 was never imported in large numbers, and OEM-pattern magazines for it are genuinely hard to find, which is a different situation than a common AR-10 magazine you can buy for a fraction of the cost. If you own an M78 and need a working magazine, the comparison isn't to a generic .308 mag price, it's to how much a non-functioning rifle costs you in range time.
Does it work in California?
No. California law caps magazine capacity at 10 rounds, so this 30-round magazine cannot be sold to, shipped to, or possessed by a California resident. We sell this listing to customers in states without that restriction only, and we verify the shipping state before processing any magazine order — see our California gun laws page for the full list of what California restricts.
Specs at a glance
Pros & cons
What works
- Purpose-built fit for the hard-to-source Valmet M78
- 30-round capacity for range use where legal
- Faster-than-typical special-order delivery window
Trade-offs
- Illegal to possess in at least nine states including California
- Will not fit any rifle other than the M78 pattern
- Longer magazine changes the rifle's balance versus a factory-size mag
Key attributes
| Caliber | .308 Win / 7.62x51 NATO |
| Capacity | 30 rounds |
| Fits | Valmet M78 |
| Manufacturer | Max Capacity Products (MCP) |
| Condition | New |
Frequently asked questions
- Can California residents buy this magazine?
- No. California prohibits magazines over 10 rounds, and this is a 30-round magazine, so we cannot sell or ship it to a California address.
- Will this fit any AR-10 or FAL rifle?
- No. It is built to the Valmet M78's specific magazine well and feed geometry and will not function in other .308 platforms.
- How long is the delivery time?
- Per the listing, expect roughly 4 to 5 days for delivery once your order ships, faster than most parts special-orders.
- Is this a factory Valmet magazine or aftermarket?
- It's made by Max Capacity Products, an aftermarket manufacturer that produces M78-pattern magazines, not an original Valmet factory magazine.
- Does capacity vary by state even outside the restricted list?
- Some states cap rifle magazines at 15 rounds rather than 10, which still makes this 30-round magazine illegal there. Check your specific state law before ordering.